If you do a search this wouldve been covered heaps of times, but here's a quick list;
Note, all these prices are off the top of my head and may be slightly off due to the exchange rate, all the brands are just the ones that spring to mind at 130am after a looooong day
Pistons: CP, Mahle, ACL, Tomei, HKS, JUN, Wiseco, ARIAS. Range from $1000 to $2000
Rods: Eagle, Autech, Spool, Tomei, Jun, HKS, Nismo. Range from $645 to $1600
Oil pump: N1, JUN, Tomei, HKS, dry sump, external moroso. Range from $500ish to $2200
Crank collar: Group buy for under $100 ea. You have to do this if the crank is out of an early model GTR. Or if your crank is stuffed (thrust worn out, cracked, bent etc) you have to get a....
New crank: R33 GTR or R34 GTR crank, genuine Nissan. Justjap had them for about $1100 before the exchange rate went crazy
Water pump: N1. Buy from forum sponsors and its cheap, currently i think Slide has the cheapest
Cams: Not needed for that power. If you really want to, there's HKS, Tomei, JUN - depending on brand you can easily blow $2000 here as some will need other parts to fit
Cam gears: Tomei, HKS, etc, check the group buy section for a thread by NYTSKY
Sump baffles: Tomei, JUN. About $500
Valve springs: JUN, Tomei, HKS. Between $500 and $1600
Injectors: Depends on size, usually the decent ones start at the $899 mark. PM me if you want some Denso/SARD's for $600 ive got a set for sale
Fuel reg: Nismo, tomei. Nismo is adjustable and $195 delivered - get that. I also have one of those for cheap for sale
Fuel pump: 044 intank, check forum sponsors, there's a DIY thread on how to install it, surely your brother can do it
Airbox: Nismo S-tune filter in stock airbox. No idea on price, its been ages since i bought that sorry
Clutch: So many options, multiplate is the popular choice here, easy to spend $1500+ on a clutch. I can very, very strongly recommend a nismo twin plate, there's one for sale right now in the for sale section that i know drives like a stocker with the guts to take 350kw atw
Headgasket: Cometic, Tomei etc - again, lots of choice. I use Tomei, costs a few hundred, comes in a kit with all the other gaskets needed for inlet etc
Head oil restrictor: Tomei. About $20 delivered
Return for oil from head: All custom parts/work, there's a DIY on this. Dont skip it, its important.
Head bolts/studs: ARP. Not sure on price with the exchange rate, FYI i paid $380 per set
Any other bolts etc: ARP have a kit for almost everything that matters
Not sure if i missed anything, but yeah add up the price for parts and thats a baseline to work from