BN01, my 2 cents...
From someone who has built a GC8 to do track work, please believe me when I say, what ever figure you have in your head in terms of maintenance and repairs, you need to double it, add 1000, then double it again and take away 2
IMO, what ever your budget is, use only half to purchase the car itself, because once it gets on the track, whether it be modified or stock as a rock, things WILL break/wear out.
I don't proclaim to be a whizz behind the wheel, but in my 3-4 years of racing the GC8 it became apparent quite early on that the WRX is quite a forgiving car. Lots of lovely safe under steer to contend with, and plenty of grip around corners. So you might say, "sounds perfect" - but the problem is that this doesn't really teach you how to drive. If you want my advice, get the basics of car handling down first, and IMO that means RWD. If I had my time again I would be going for an S14 or one of the Silvia families. They're cheap (depending on vintage), lots of spare parts around and a much less forgiving car to drive (read: you learn much more valuable lessons). Once you've got the basics down, then go for the 4WD EVO, WRX, GTR woteva and apply the rules you've learnt - I guarantee you'll be faster for it.
My final though, don't think that woteva car you buy now to track is going to be the car you'll always race in. With that in mind, buy something cheap like a 180SX, don't spend too much on it (save it for repairs and maintenance) and just drive it. 'Seat time' is what it's all about - because after a while you'll be beating people who have spent $$$$$'s on their car, but just don't have the experience to peddle the damn thing.
Here endeth the lesson!!!
Al