So, I didn't go through this whole thread to see what has or hasn't been suggested, but Aron was asking about it earlier and I didn't really have any good ideas, except one and really it would be a horrible idea, but given the in-game maps you've already chosen, I was thinking Despot and Powcamp would make some lovely zombie maps. Mostly because while you may find a spot or two that would make for some good camping, ultimately I don't think you really got anywhere to go, but who knows. They're small maps, so that should help. I'll think on it some more and get back to ya.