Depends on what you mean by "proof," don't you think?
I'm going to go ahead and say "Agnostic Theist" because I'm guessing by "proof" you mean typical scientific, empirical data. A God that could be proved that way isn't even worth believing in...
EDIT: Interesting, same proportion of "Agnostic" to "Gnostic" in both Atheist and Theist.
I definitely believe there's alot of merit in the circumstantial evidence of creation, the way the Big Bang occurred, the nature of existence, etc that proves God to those who truly understand the arguments, and a God who couldn't fulfill those criteria wouldn't be worth believing in. But of course that's nothing like the type of proof I referred to before.