Didn't see much life in the turbo section, so

Ok. So this is a legit honest ask for help. I really have a pretty good handle on cars and working on them, and anything i can't do, my buddy knows how to do. I drive a 2006 Lancer SE 5sp. I am looking to buy a medium grade turbo kit. I don't know what logistics i should look for, but i've heard that if i want to run any more than 7-8lbs of boost, i'm gonna have to get rid of the stock pistons. the engine is a 4g94 engine, with no mods yet. I had thought about a CAI but wanted to wait to buy the kit this summer. Also... Exhaust systems... cat-back have no idea what that means, Catylic converter? idk. Anyway i'm looking to spend some money, but wouldn't really like to break the bank. Any suggestions would be nice... Have heard good things about garret turbo systems, but they are pricey? Thanks a lot!