25DE head, good condition bottom end (get the crank reground just for peace of mind, cost me $120), I've got forgies but I got a good deal on a block/piston/head setup.
Use everything off your 20 (25DE intake manifold ports are slightly larger but it's only a bee's dick worth).
I'm running a 25s1 turbo which I had on my 20. Becomes a major restriction at about 5800rpm where it falls over harder than it climbs. Could have lent on it a bit more but would have only caused to turbo to fall over sooner.
Making a super torquey 183rwkw with 12psi by 2200rpm.
I had it running on the standard ECU but needed to use a group-buy remap chip I had because it was hitting R&R pretty much straight away.
I was also maxxing the AFM at about 6000rpm.
So, I got myself some 550cc injectors and a z32 afm and had my ecu remapped with a bit of a tune to throw in a bunch of fuel down low so it didn't lean out when it came on boost hard.
Quite fun to drive but should be a lot more fun with the GT35R strapped on the side
As far as wiring goes, if you use an R32 RB25DE head, everything plugs straight up. We did my conversion in a weekend and I drove it home very early Monday morning on the stock ecu