just get some of those china spec headers for the n/a off e-bay

it you're going to do turbo conversion buy a gt foz or wrx front cut and swap the whole motor/ecu/gearbox/diff

the amount of stuffing around with just bolting on a turbo kit is just not worth it, you'll need to re-tune your existing ecu to suit the added turbo, your existing block/heads/comp ratio are not designed to handle boost so i wouldn't expect it to last very long even with as little as 8psi boost