U can use either rb20 or 25's loom.
Rb20 loom u will need the ignitor and coilpacks from an rb20, u will also need to get a vct controller. and u can use the rb20 ecu also
If u use the rb25 loom it will need to be modified if u use the rb20 tps (swap plugs) and the z32 ecu(NIStune) will need a special base map loaded onto it to suit the rb20 tps