mitch if you want to nistune, you will have to use a piggy back Z32 board iirc. some stags have slightly differing batch number computers, which can be a prob.
IMO go MV automatics shift kit. S1 boxs are one of the strongest. btw the professors look mint, you' ll need camber arms def though to achieve the tougher stance and save inner tyre wear when factoring in the wider rear track.
R33 sway bars need to be slightly modded to fit, but is one of the best mods (preferably with sydneykids setup), dunno about this mix and match gtr stuff being recommended but few have done it, chuckies seems ok. I prefer stiffer spring rates and braces, body roll is shite in a wagon. choosing from the tein and whiteline catalogue will save all the headache.