Why don't you create a deathmatch server with multiple maps? The actual Dust2 DM is pretty nice but it might be cooler to have a deathmatch on office or assault, for example.
Also I wanted to propose a deathmatch on a map called Crackhouse. None of the non-steam servers has that map and it's actually a very nice map for a deathmatch.
I hope you consider this and thanks