Spend your money on a nice header, cat-back, and a better flowing filter. Later tune it and be done with it. Tuning will probably show the most gains, and you can add NOS like my buddy did to his K20 hatch w/ k-pro. I think he did 220whp on kpro street tune with header, test-pipe, 2.5 catback, and aem intake. Since then he did 06 si intake manifold, more street tuning with the varialble cam timing this time, and a 50 shot and did like 296 or 306 at the wheels.