I've had my GTR for close to 2 years now and I love it. I used mine as a daily for about a year and racked up about 40-45k kms. Got about 450km to a tank. I bought the car pretty much stock with just a catback. Since I've owned it I've put in some new Bilsteins and superpro bushes but thats about it. I've had no problems with the turbos but my car is still running stock boost so I never expected any.
If I was looking to buy a GTR now that is close to stock my criteria would be:
1994 model. They have the wider oil pump drive like the R33s and 34s
Replacement turbos. -7s, -9s or N1s they're all pretty similar,
After market computer - Power FC, Nistune etc
Good service history
That would give you a solid base to work on and should be fairly reliable. The good thing about buying a GTR now is the market is dead so there are a lot of really nice modified examples for fair prices. Have a look in the For Sale section on here and you will be suprised what you can get for your money these days.