IIRC greg made around 180 at the wheels with a thirty bottom end high comp and itbs.
Mate in machine work, buying the products and trying to find a tuner and ecu to suit the itbs (good luck) expect big money and a lot of time refer to screamins rb20 for itb knowledge, took him 2 years to get it tuned and set up properly.
It's ur car man, I've been down the NA root and decided against it (well kinda, going big capacity ;P). If you have the money there (and I'm talking a lot of money lol) go for it. Better yet go and talk to a fab/work shop and get there opinion.