We used different sources for research, so the list may be incomplete. If anyone knows (inhabited) places for the remaining letters, feel free to let me know and I might add them to the quiz.
I think the final letters will be really tough, but a related quiz idea - how about the (say) 20 largest cities with alliterative names? And for the whole world?
About your other comment, just typing "nd" would have worked for East End, since the "E" is already given as first letter.