Simple things for more power included-
-91 intake cam go for around 50 shipped. Or just Get JWT or Brian crower cams.
-pop charger JWT or Stillen/ebay intake/ cold air intake etc.
-SSAC header or a used hotshot. SSAC is the best bang for the buck. Under 150shipped
-Exhaust from VRS or get a Greddy SP (great exhaust i had one)
-UR pulleys crank and water pump 2piece set.
When i was n/a i had injen cai, JWT S4 cams, Greddy SP, G20 ecu, and ssac header. It was noticeable difference from stock.
Start here-
http://www.sr20forum.com/forum-index.php