Neither one of these cars will allow for test drives so it's a little difficult to make my mind up on which one to get.
I have never actually been in the market for either one of these cars, but if you are buying from a dealer I don't see how they won't let you test drive one... that is what dealerships are for IMHO. I can understand if you are getting used, but even then I wouldn't buy a car I hadn't actually driven no matter how nice. I guess the only exception would be if I was ordering a car, but I would drive the same car at a dealership to see if I liked it before ordering one. If the person you are buying from doesn't let you drive it then I would suspect that something is wrong with it and unless it was an extremely nice deal I would stay away. Just my thoughts on that comment.
I would go for the GT500 if it were me, bigger and heavier, but I think for the 200mph goal it will be more likely to do both the 200mph and the daily driving stuff.