Turbo selection: I would definitely go the GT3076R, with the 0.82 rear housing . Have it on my rb25/30 and couldn't be happier with the response and power. Currently my set-up peaks at 20psi and drops to 16psi, by red line, and is making 325rwkw; with the same response (if not better) as a totally stock rb25.
My engine has been fully built, though, and has all the "bells and whistles".
I am now going external gate, to hold boost steady till red line and see if i could get more out the package.
Need to ask:
What's so special about a "RIPs block" if all internals are standard? Seems to me, like a major expense for little benefit, if you're not going to build a "full house" engine . A block is a block, as long as the machinist does his job properly and is thorough.
PS: With your 4WD, you'll have an awesomely responsive package, that would be stupidly quick; you will not be disappointed!