I'm currently looking at Art of War Central. Supposedly you get unlimited bandwidth for games, although I don't know if that only applies to games on their list. I'm going to run Windows server 2003 on it and get a RAM upgrade as well. I'm getting one month initially so I can monitor system performance and figure out if I need to buy more ram or bandwidth or switch to a new host.
I also looked into UCV host. If you have any suggestions I'd be happy to hear them. I plan on running a 32 player server so I'm not sure how much ram I need.
Edit: 2 mumble servers, one public (24 slots) and 1 private (8 slots). I expect these to use a trivial amount of resources however.