How set are you on one of the included campaign models?
I have a great idea for a campaign thta would have lot to do with monotheistic christian religion (not at all in a mocking way, I am christian myself, I just mean that I would use the cosmology, so to speak). It dosen't fit too closely with any of the included settings, but you could think of it as Urban Arcana meets In Nominie meets Classical Christian Writing. I knwo its kind of out there, but the d20 modern rules strike me as a good fit, and I am really excited about the concept. Even if you don't really like it, I will still probably run it (or at least try to drum up some interest), I just thought i'd propose it here first.
Ankh-Morpork Gaurd, your also more then welcome to play.