Well ... if I had the money, I'd buy a 993 Turbo S
But that's not the question for the moment ... I think I'd buy a 996 Turbo S cab instead of waiting for the 997 TT
GT3 gets my vote. A driver's car for sure and you won't loose too much money when you trade in for a 997TT. If you get a 996TT the depreciation will be more than a GT3 compared.
Id go w/the Turbo now. There is no reason to wait untill the 997 turbo comes out. If you have enough money to throw down on a 996 turbo then the upgrading Idea that everyone is saying would work perfect. You will be in no way dissapointed by the 996 tt, they are simply amazing cars that go like hell. If It were me on the otherhand I would go with the GT3, 380 n/a hp 8200 redline............. but very different cars. Good luck with your choice.