You could easily find a Mk2 GTi, might be a little tatty with high mileage (not something to worry too much about), but should manage to get a decent enough car with MOT. You might manage to find a Mk3 GTI for that price, but it's more likely to be in a sorry state and if all you can find is 8v Mk3's you'll probably be disappointed with the power of it. But if you want more modern looks and comfort it's the one to go for.
My money would be on a Mk2 GTI though. More fun for little cash.