A friend's father has the Ford GT: it looks nice but as others have noted, the seating position is awful. Looks good as an overgrown Matchbox.
Can't say much about the ZR1, except that my uncle's good friend had a 91 I think, where the zr1 package added $30,000 to the cost. This was in 95, and the guy had just bought a Supra TT, which made the ZR1 look absolutely meager in comparison.
In conclusion, I'd want neither, and would opt for the aformentioned Supra.