I've searched the forums, but I didn't find anything.

What are the best things to buy for it performance wise besides turbo, that won't destroy my engine and isn't to expensive.
I want power but I want to keep good gas mileage.

 

is it an EX or Si? Anyway, best starter mods are intake/header/exhaust

 

you didnt search that hard then, a turbo isnt going to ruin your motor either if you do it right