Ahk, you can either use a Z32 ECU and find someone to install who has done them before (need to swap a few pins around on the ECU plug)
or and R32 RB20 (gtst) Ecu, easiest option as it plugs straight in, but Rb20s do not have the variable cam timing, which is where the MSD window switch comes in (you use it to switch vct on and off, on at ~1100rpm and off at 4700rpm)
You dont need the software unless, as you say you want the software on a laptop, It is handy if you want to run E85 and PULP as you need to change the maps
No functions lost, will retain A/C, power steer idle up etc etc
so it is all as per factory (it is a factory ecu after all )