Personally I wouldn't go for Hybrids, I've seen too many folks spend good money on hybrids only for them to fail shortly after. The quality of them seems to vary a lot. Stock j-spec turbos are more dependable IMO.
Whoever it was above that thinks he's hitting about 450bhp; which uprated injectors are you using? The stock j-spec injectors can't flow enough fuel to make 450bhp, not unless you've raised the fuel pressure way above stock anyway.
There's a fair difference between bhp at the hubs and at the wheels. My old Supra made 350@hubs and 300rwhp.
Is anyone going to the SRR day that has previously had their car dyno'd at the hubs and still have the same mods? It would be interesting to see if your results are also more realistic at SRR.