go the rb25de brenton - bolt all your shit on, and do your manual conversion. should still have cash to spare.
needs to be the 32 rb25de though, as 33 one has vvt of something i think and the rb20 wont suit.
go talk to terry at kansai - he is building up the rb25de right now for the cefiro! with H/G, big turbo, inj, comp etc...
OR if you really must - he's also got GTR crank and rods down there if you are to go the 23/24 route.
I have the 24 in my ceff - just had it all tuned (results in RB20 power thingo) BUT - i was lucky, all i had to do was buy the block and freshen it up, not get all the machining etc done otherwise it would've been too $$$ for me.