I think you could get a nice NA for £7k mate, but for that money you could also get a TT, albeit maybe a little older. After owning both, I would plump for a TT any day, just be wary that your insurance will probably go up as will running costs (not by masses though).....
For some reason the Supra market is really slow right now, so you will be able to get yourself a bargain, probably one from this site. There are a couple of TTs for sale now for your budget in the for sale section, so it might be worth checking them out. At least buying from a member will give you a little more confidence as you would hope they have looked after them properly....
Spec wise, I would say your looking at the older end of the market, but specs are so different these days its hard to say. I would personally be looking for a relatively standard car, with as low a mileage as possible, Auto (I just love Auto's), in black or silver......
Not a great deal of help, but there are millions of threads on the subject of buying Soops. Do your research before buying - thats the best tip!!
Nick