1. Auto Skylines are gay.
2. Get Manual, you will DEFINATELY not regret it.
3. You dont need a 'health' check every month.
4. r32? for 15k? You can literally go buy an R34 GT-T for that.
5. R32's are alot older. I personally reckon they have more problems, i've had 2 33's and they had problems. 0 problems with the 34. My saying is, the older the car, the more problems.
6. Petrol will be a bitch. depending on how much power. expect 350-400km (60L) out of a stockish GTS-Turbo.
7. Go on carsales, whatevers cheaper/cleaner. buy it, make sure you do a mechanical check cos most of em are thrashed.
8. Manual, if you know auto, you'll learn it within a few days, after that is just 'perfecting your manual' but you will be fine after a day or two. you may stall a few times, but eventually realise how easy it is to drive.