Originally Posted by Zorin
mostly handling and power.
For handling, I would say the H&R cup kit is the best bang for the buck in terms of handling. Under $1000 for a set of matched springs and shocks made in Germany. Hard to beat.
For power, your best bet is probably an GOOD intake kit (with a heatshield) such as ECIS's kits. My other choice would be software like the Shark Injector.