hey Ben,
Many jap-brands sell direct-fit injectors for rb25det, i just bought some NISMO 740cc injectors which are direct fit.
I went to fit them today, and found the job abit complex, but the looks of it there are 4 nuts on the underside of the plenum which will need some-sort of tool which can bend into that place.
Once those 4nuts on the bottomside are remove it looks like you just have to plugs the hose etc and then remove the fuel rail and replace the injectors (i was advise its best to take the fuel-rail off the car which changing the injectors)
Im going to give to another go 2morrow, and see if i can find a tool which will undo those bolts
Cheers Michael
Ps i was quote by a local workshop $300 to change the injectors