There aren't many mods for the v6 that aren't expensive. Comptech has the supercharger and one of hte only headers that i know for the v6. Other mods you can do are changing the ignition wires, AEM pulleys, and nitrous.
If you want the most bang for your buck...go suspension. That usually is the most noticable change. TEIN makes the best suspension upgrade IMO but it's a grip.
Neuspeed makes a great upper strut bar and you can always do the TL-S sway bars switch. Other than that.....well....be creative and good luck