p30 or jdm p73 pistons would be ideal for your setup. both would put you in the 11.5ish:1 range. 200whp with itr cams is certainly doable, but would require a very good tune. if you want more than 200whp, you'll need to look into bigger cams and matching valvetrain. i like the rm m22x, and skunk2 pro1.

you'll also want a good flowing header with a 2.5" collector and matching 2.5" exhaust to prevent bottlenecks. then something to tune with. there are many options out there so i'll leave the research up to you.