I really do miss my 455 TransAm. On the plus side, I do still have a GrandPrix with the 455/4 bll V-8. It's a little more comfortable, but does not handle as well as the T/A.
I almost forgot about your hypothetical 50,000 pounds of currency ... hmmmm ... First, I'd buy a 2004 GTO. Then I'd pick up another GTO ... maybe a 455 H.O ... then I'd pick out either a 455 Super Duty Trans Am, or a nice land yacht ... like a GrandVille convertible. (Are you seeing a Pontiac theme here?)