well if you use the si ECU and an autometer shift light it'll prolly be cheapest. i think the lights are like 80 bux and the pills (little chips w/ different RPM settings) for it are like 30 for 10 (they come in packs like 3000RPM-4000 RPM)

my buddy has one i'll see how much he wants for it if your interested but he only has the 8k-9k pill pack (used the shift light w/ his old b16)