... says:
Interesting choices. You may actually be interested, if you can't find an original GT40, to look at the modern remake, the Ford GT (Not to be confused with the Mustang GT).
As for the Viper, there's a factory mod of the SRT-10 called the Hennessey SRT-10 Viper Venom 1000, which hits over one thousand break horses and in an unofficial speed test hit 230 at the speed trap in forth gear. If Hennessey were to take it to the salt flats, it would likely dethrone the legendary Bugatti Veyron.
Yeah i know of the Ford GT, but it still dosen't "out class" the classic GT40.
The henessey is a beast and your right it may beat a veyron in a straight line.
if i was to pick a favourite viper the old 90's SRT10's would be my pick.