Personally, I don't mind the R33 4-door, it's the coupe that looks a bit 'off' (sorry mum & dad...).
If you need to maintain some semblance of practicality, then you'll probably want to keep the '33. Going to a S30 with no steer, probably no air (well pretty average ventilation at best), less sophisticated brakes and suspension will probably get on your nerves if it's a daily.
I'm not saying 'don't get one', I'm saying consider keeping the '33 (or something similar) to do your daily work, and make the Z a weekender.
I have driven my 240Z as a daily in the past (for several years in fact), and it doesn't take long to desire something less 'special' to do those peak-hour commutes (then I get withdrawal-symptoms, lol).