I might be mistaken, but isn't that the show where they perform on a floating stage? If so, I've got a copy of it. I think it is a 2nd or 3rd generation copy. The overall quality isn't too bad, but since it was televised you would think it would be a little better. By the way, if you have not seen it yet, wait till you see David sing
WYWH... He forgets to start singing!

Anyway, I'd try looking on ebay or something like that. I got mine thruogh the now extinct "Brain Damage" magazine/fanzine back in 1993. Good luck hunting!
~Brian~