Give me a list of import tuners that has easy cheap mods and best gas mpg?

looking to buy a used car that has good body lines and easy cheap mods to run 12s and kinda want a 4 door that will get around 28mpg or more a two door will work and i don't want any thing later than 1990 mean yeah i would love a skyline or something but i need something around $4500 - $6000 car lot price in mo