here's my advice. ive done some training and have been a fight fan for a very long time. if you want to fight MMA, I suggest going to a gym that trains MMA. most of them have seperate classes for jiu jitsu, wrestling, kick boxing, and an MMA class that ties everything together.
what to look for in a trainer: check out their credintials. are the black belt in any martial art? who did they get their belts from? do they have a professional record? those things are good to know and easy to find out, typically. the thing is, if you have a guy thats a black belt under some big named fighter, like a Gracie, they are usually quite expensive to train with.