Hmm I am surprised that SimianCage.net isn't on here!
It's a great community from the UK and they had a custommaps server for ages!
Currently they added a second server so more room for testing!
Anyway this is their mapping forum: http://www.simiancage.net/forumdisplay.php?79-Mapping
The mapping forum is only accessible for registered members tough so your secret mapping projects are safe!
Well, i'm going to try my favorite clan, i always play in the servers and i know the peeps there. AEROLITE GAMING! (main tf2 place, but they'll be happy if you posted acutal maps in suggestions and feedback, i think.)
It'll be hard to try and get them to do it, because quickplay is kind of the lifeline of our servers, and payload server will occasionaly be empty for long periods of time.
Has 3 servers: all-2fort, all-turbine and payload-vote (wich is pretty much frontier or badwater when i'm on, somehow people are very easily manipulated by "Vote 5 and get cookies!").
I feed on the stupidity of people, that means that i am never hungry.