Great car to own, a real weapon. Obvious question is why are you selling and what mods have been done to the car and who and when were the mods done.
As others have said the R33 GTR started in 1995 so your first car described is either a fake or a typo.
Personally if I purchased another performance car that is 10+ years old, I'd get one modified already as there's so much cost involved in replacing old worn parts. I would also look at the for sales section of this forum as a primary place to buy a car, more owners on this forum care about their cars, hence they join a forum to lean about their car and their cars are in general a better quality to those who don't care to learn about their cars.
Another to look for is a mature owner or at least a owner with money. To many kids buy skylines with no money and fail to maintain them.
Where are you in Australia so the forum can suggest possible cars to have a look at.