This will depend in large part on what you hope to achieve. Both Krav Maga and Muay Thai have a particular focus. "Which is best" type questions do not work on Stack Exchange. "Which is best for this thing I'm trying to achieve" do work.
I won't discuss the relative merits of Krav Maga vs Muay Thai, since each has a particular focus that it is best at. However, if your ultimate aim is Kali, on the surface I would say that Krav Maga would suit you better since it at least includes anti-weapon defenses. The caveat to this is that you may learn techniques that fit in with a Krav Maga mentality and methodology, but which do not work for Kali. You will then find yourself in a position of having to re-learn what you thought you knew.
Although there may not be a Kali school near you, you may find Kali or Escrima seminars being given in your area. Ask around at local dojos. A lot of the taekwondo, karate, kung fu, etc... schools in my area also host Kali seminars. It is relatively rare to find a specifically Kali school. You may, therefore, desire to practice a supplemental art that will keep you in shape between seminars. Which one you choose will depend on your fitness level, fitness goals, and individual preferences.
for your second comment, It is a matter of money, I can only afford one of them.
– mewais Apr 29 '14 at 21:47