I'm going to be unorthodox and say James Dean. He's not British and he died around the same age as Russell Tovey (who I think is too young to play the Doctor) is now. But Dean had a presence that seemed out of time, in a way. He seemed much older than his years at times, while also having a childlike energy. As long as he reigned in the angst, I think he could have done some really interesting things with the character.