Undiscovered

Unless you want to be racing it, stick to the AWD. Main advantage is increased traction, it'll "hug" the road better than a RWD. Also, RWD cars (namely sports cars such as the Skyline) are known for being prone to spin out in wet weather. The AWD has a much less chance of doing so. AWD is much safer in that regard. Your car is exactly what I'm looking to buy. How much did you get it for?

Also, last I checked (correct me if I'm wrong), but all R33 GST-4's are non-turbo.