Good Luck Gaz, I picked up my old NA for 2k and never had a problem with it, it was relatively cheap to run also. Insurance isnt too bad, I would highly recommend Sky Insurance on here for a quote, they are the cheapest around that will insure me and give me a brilliant quote on my VXR (atleast £500 cheaper than anyone else).
Scott is right in what he is saying regarding costs though (even though my post above may contradict it in some ways, I guess I was on of the lucky ones to pick up a decent 2k one). The Supra is a lovely car to own, drive etc but you need to respect that it is a sports car (albeit an NA) and if something does go wrong then it can cost you, so make sure that you do have the money for back up available should you need it.
Good luck
PS Jurgen only stocks the best, hence why they may seem more expensive than some likely sheds advertised on PH, give him a call and have a chat with him, let him know your budget etc, I'm sure that he will be able to advise you on what you would realistically expect to pay for the supra you want.