I would go with a helix uppipe and catted downpipe, if you want to keep a cat on your car, if not go catless with a O2 fix. Gruppe-s sells the kit - up/dp/O2 fix for $450, I have a STP catback exhaust, I would go with any 3" exhaust kit, personally perference.
With that alone you will be screaming, that is what I have and I touch the pedal anytime above 3 grand and It pulls!!!!
I can't imagine what it would be like with a UTEC!!!!!
my .02 is to get your ECU reflashed either send it away or get a ECutek. The reason being that if anything goes wrong with your utec your engine might get blown up and the ECU and engine will be more reliable.
let me know what you go with!!!