I'm not sure we should formally support street racing honestly... a few stories slipping through the cracks is one thing, but a dedicated forum is quite another.
I took my stocker to 17.75lbs from 23lbs, with most of the material removed from the outside. Make sure that there are no sharp edges when it is machined out, it should have a nice radius to it. This mod made a huge difference in my car and was well worth doing.
I am not sure I'd take the stocker any lower than 17lbs though. If you want to go lighter get an aftermarket unit.
I broke a 240z stub axle without being terribly abusive... open rear end. I'm not making stupid amounts of power either, I'd guesstimate ~240rwhp and 280ft-lbs.
http://www.sdsefi.com is their website. Lots of info there including prices. (and my car as former project of the month!)
SDS is a bare bones stand alone engine management system. It comes in both fuel control, and fuel & ignition control formats. The big selling points are that it is inexpensive, and you don't need a laptop to program it.
If you guys end up with a small group, I am an SDS retailer and can get you guys discounts that may be better than what you can get with 4 or less people. Just food for thought.