I nominate: Ryan Cartwright
He's English (which I believe is a BBC requirement)
I don't think there should be a female Doctor nor a black Doctor, only because there hasn't been one. We don't have to make these choices just "because". The Doctor's DNA is basically (white) male. And while over 11 Doctors, all his cells are replaced, they are replaced by the same XY chromosomes. Again, just my opinion.