Check out jdmracingmotors.com for the motor itself. What motor do you have now?
EDIT: Saw your other thread. You could either do some light engine work to help with reliability, then boost it, or you could go the N/A route. If you go N/A, I know someone you need to check out/talk to. If you've been around Ludes and the prelude forums a while, I'm sure you know who I'm talking about.