[Muscletang]

Do they still make S-351s? I'd go with that myself, but I don't know prices or performance figures. I've heard those things are ungodly fast and quick though.

As for picking between the two, it depends on what you want. The Cobra (I think) is a good base line car and responds well to mods. The Saleen is expensive because (I think) you're paying to say "yeah, this is a real saleen I got here."
In the end it's up to you, but I'd think I'd get the 03 and mod it up.