Energy weapons
There are a lot of options for energy weapons, but few of them are good, and fewer still work with barbarian.
Soulknife
The “Elizabeth Braddock, a.k.a. Psylocke, class” is soulknife. From Expanded Psionics Handbook, the soulknife wields a mind blade, a weapon forged of pure psionic might. Described as a quick, mobile, lightly-armored skirmisher, the soulknife is somewhere in the monk or rogue territory of class concepts.
It’s also quite possibly the weakest class in the game. The mind blade amounts to being a mediocre magic sword, and you could consistently just buy one as good or better at most levels. Its damage boost, psychic strike, burns a swift action, is only one per round, and is mind-affecting so huge portions of your potential enemies are immune to it (a problem sneak attack also has, but which a rogue can work around with penetrating strike or wands of golemstrike and gravestrike—the soulknife has no such options).
And on top of that, soulknife and barbarian basically don’t synergize. Psionic feats—about the only privilege the soulknife gets from their psionic status and one of which they get as a bonus feat—rely on psionic focus, which you definitely can’t gain in a rage and may not be able to even maintain in one. Barbarians typically want big two-handed weapons, but you can’t turn your mind blade into one until you’re a 5th-level soulknife, and even then it’s a poor one (bastard sword), so you wind up burning a feat on getting the mind weapon you actually want. You could maybe do some throwing synergy, but that isn’t your concept and there are vastly better ways to build a thrower.
The soulknife also has no particular options for touch attacks.
Brilliant energy
Brilliant weapons pass through nonliving material entirely, so they ignore armor and shield bonuses to AC, effectively making them touch attacks against many foes—but also making them useless against (most) constructs and undead. They’re also ridiculously expensive.
Wraithstrike
Wraithstrike is a 2nd-level spell that turns all attacks for 1 round into touch attacks. That is a great option, and with a wand and Use Magic Device, you can get it at a great price on most characters—except barbarians.
Eldritch glaive
A warlock can turn their eldritch blast into a glaive and make a full attack (sort of), plus attacks of opportunity using the eldritch glaive blast shape in Dragon Magic. The glaive retains the blast’s touch attack property, so it checks that box. This is the best simple option for Psylocke—but invocations like eldritch glaive are spell-like abilities, and you can’t use those in a rage. It’s also not clear that you could use it as a bear. So those probably nix this option.
Turning into a bear
There are a lot of options for this, and several are pretty good, though there is one stand-out choice here.
Bear warrior
The bear warrior prestige class from Complete Warrior turns you into a bear when you rage. Simple, effective, and synergistic. Comes with massive amounts of Strength. Also good at grappling.
Polymorph, wild shape, etc.
Various other shape changing options are generally more expensive, and more powerful, so you would probably not really want to use them just to turn into a bear when you could turn into much more powerful things.
Metamorphosis
The psionic version of polymorph, metamorphosis might be more fitting for Psylocke, and may be easier to work into a multiclass character. Can’t be used in a rage, but you can use rage while morphed. The bear warrior is probably still better for this concept.
Eldritch Claws and Beast Strike
The Eldritch Claws feat from Dragon vol. 358 does not turn you into a bear. But it gives you claws that do good damage, and can be used while raging while also benefiting from eldritch blast (they scale with eldritch blast damage but aren’t a blast shape and don’t require invoking anything). A barbarian could do well with these. Since the claws also scale with unarmed strike damage, boosts to that can be useful, as can size increases—so bear warrior might still be nice.
Eldritch Claws do give up the touch attack nature of eldritch blast, which is a shame. That said, as a barbarian, or especially as a bear warrior, your Strength should be massive and so you should not have much difficulty hitting armored targets.
Beast Strike (Dragon vol. 355) allows you to add your claw (or slam) damage into any unarmed strike. Since your claws from Eldritch Claws are already based (in part) on unarmed strike damage, adding them to your unarmed strike damage means you double your unarmed strike damage. It also means you can get iterative attacks, where claws are limited to once each. There are a whole lot of theoretical possibilities with Beast Strike, since it’s not a super well-written feat, but even at its most basic, under the most conservative of interpretations, it’s still a pretty good feat.
Conclusion: barbarian/warlock/bear warrior
Your options for your first 5 levels are basically barbarian 2nd/warlock 3rd or barbarian 1st/warlock 4th. Two levels of barbarian gets you more hp, slightly more BAB (with fractional BAB, without they are the same), better saves, and uncanny dodge. Four levels of warlock gets you the ability to take 10 on Use Magic Device checks, which is fantastic if you have ambitions of using Wraithstrike, and also puts you closer to higher eldritch blast damage and/or better invocations if you continue to advance invocations after this point.
Either way, at barbarian 1st, you want the city brawler (see below about feats) and lion spiritual totem (Complete Champion) variants. Take eldritch glaive at warlock 1st: it’ll be awkward, but you can activate rage after invoking eldritch glaive but before actually making your attacks. You’ll have to end rage (and become fatigued) if you want to use eldritch glaive again, which is painful, but that only lasts until warlock 3rd (or your first feat after warlock 3rd, technically), when you can take Eldritch Claws.
(For those not starting at higher level, this works better if your DM is lenient with retraining: you can trade in eldritch glaive after you have Eldritch Claws, and you can (with a reasonably generous DM; the official PHB2 rules wouldn’t allow it) retrain a feat for Eldritch Claws once you’re a warlock 3rd, even if you wouldn’t otherwise get a feat at that level.)
Feat priorities are Eldritch Claws and Beast Strike, as discussed, though Beast Strike will have to wait until 9th. You can get Improved Unarmed Strike and Two-Weapon Fighting for free as a city brawler barbarian (Dragon vol. 349), and Improved Two-Weapon Fighting from gloves of the balanced hand (Magic Item Compendium). Superior Unarmed Strike and Snap Kick (both Tome of Battle) are also great options.
Bear warrior remains a decent option, but you don’t qualify until 8th at the earliest. You’d like to advance spellcasting to improve your eldritch blast damage, but it’s not crucial. Sneaking into abjurant champion (Complete Mage) might be a good idea, but you’ll need to work that out with your DM since it requires 1st-level spells and you don’t (technically) have them. Alternatively, advancing unarmed strike damage would be even better; Shou disciple (Unapproachable East) could be really good, and you could even take it at 6th, though the feat requirements are a pain. Or both with enlightened fist (Complete Arcane), though doing it early will require fractional BAB and a dip in monk (so barbarian 1st/warlock 3rd/monk 1st—note the chaos monk from Dragon vol. 335), and also delays bear warrior to 9th due to the BAB requirement.
With flaws to make the feats bearable, I think my vote for 8th level goes to barbarian 1st/warlock 4th/Shou disciple 2nd/bear warrior 1st. Finish bear warrior and Shou disciple for the rest of the levels. Without flaws, I would go barbarian 1st/warlock 3rd/monk 1st/enlightened fist 3rd at 8th, though missing warlock 4th would be disappointing and not being able to start with bear warrior is a bit out of spec (you can take it at 9th).
When you can afford it, a torc of lucid raging (Dungeon vol. 126) would be a good choice to enable invocations while raging. You could even use eldritch glaive with it, though you would have to choose between that and Eldritch Claws. You also have the option of zapping a wand of wraithstrike at this point. Before that, many invocations have 24-hour durations, so they’re ready to use before you ever enter a rage.