Well, you could go...
Rebuild from bottom up, nismo bearings, custom block mods, acl race rings, balanced and blueprinted, arias 20thou oversize pistons, arp 2000series bolts and studs all around, nismo gtrn1 oil pump and water pump, cometics triple layer metal head gasket, ported and polished head, tomei camshafts 256degrees, tomei valve springs and retainers, custom stainless steel exhaust manifold and screamer/dump pipe, turbo smart 50mm wastegate, garrett to4z 800hp moded turbo, custom intake from outside, BMC airfilter, custom 4" dump pipe from turbo, 4" cat to 3" custom stainless steel exhaust and apexi muffler, Greddy manifold, custom gm 70mm throttle body, 2 1/2" intake from intercooler, 2x turbosmart type II blow off valve all powder coated platinum silver, gtr intank fuel pump, 2 x bosch 044 fuel pumps, surge tank, 2 fuel lines with all speedflow dash fittings, custom fuel rail with 2 autometer fuel pressure gauges, 1700cc bosch injectors, nos wet system 50hp shot "not used yet", bosch motorsport fuel regulator, cryo2 intercooler spray and purge
All in front of a Standard 5speed manual. This is all on a existing RB25 r33 that makes 800hp on NOS.
But there are sooo many options you could take! It is going to be difficult for some to provide you a exact list without criteria. And if someone does, it might not fit your budget. Then your going to get the next expert telling you the first guy was all wrong!