In regards to place, I personally would say that we shouldn't use an already established city in the Dresdenverse if we want to be creative. Sure, it'd be easy to make use one as a baseline, but I think it would be much more interesting to try and make something more original, build our own little piece of the universe within its parameters. A couple ideas could be from cities with histories of Supernatural activity of various sorts IRL. Savannah, Georgia is a big city with Ghost sites, Boston had its pre-colonial history of the Salem Witches along with other cases, or New Orleans has a thriving Vodoo and Witch Doctor Community. The point being that we could try to use pre-existing things in other cities to try and make them fit into the Dresdenverse. Just a thought.