Likely your research for those upgrades won't be best done on hybridz, I would poke around some of the 300zx specific forums listed above for answers to those questions. We don't have a lot of 300zx people here, and even fewer that have held onto the VG30 in some form or another. That is not to say you aren't welcome here, you'll just find the 300zx knowledge is pretty small here in comparison to other cars, engines, etc.
With that said, I'd be looking for a junkyard motor, or a wrecked 300zxtt to take the motor out of, and there are a number of turbo upgrade kits out there for that motor from Stillen, HKS, etc.