I personally would not have a 996 or 997 turbo, as they are NOT the car you think they are. They are WAY too soft and not really suitable for any kind of track work as standard.

However, if it was the choice between a brand new GTR or a second hand 997 GT3, it would be the Porsche everytime. It might mot be quite as fast, but it has much more depth of character and doesn't do everything for you in the same way the GTR does.