For location, I'd pick Chicago. It has always worked the best for everyone involved during the heyday of the IDL. Now, I am not sure how geographic spread has changed, as there were relatively few euros playing then, and maybe by comparison now we have a lot more overseas candidates.
Providers I don't know anything about. I'm sure the bill footer would make an educated decision. It's only a Doom server after all. I can't imagine it's very sensitive unlike say, a CS 128 tick server would be.