Cam gears are not hard too install, but you'll need to get on a dyno in order ot tune them. As for a header, if you're after peak, top-end power, go with the 4-1. If you're after more usable mid-range power on the street, go with the 4-2-1. As for brands, DC, A'PEXi, and GReddy make nice units. The JDM ITR 4-1 will also bolt up with some modifications. If your stock plug wires are old or worn, I would replace them with new stock ones or NGK's(NGK manufactures the stock Honda wires).