intake, exhaust are the obvious places to start. i don't know if they make a "chip" for your vehicle, but i'd look into that, changes the timing and a/f ratios to a more aggressive, performance oriented curve

after that.... either mild forced induction kit, engine internals, or the cheapest of all..... nitrous. i've got a complete, nearly new (used less than 10 times) zex dry kit for sale if you're interested, PM me 300 obo.