There ran for a while 5vs5 bomb server and got moved to TS mode I think. IMO 2nd bomb server is a good idea, because in the evenings 1st one is often full. The second one could be just set up with mapcycle composed of maps from CS only (map voting turned off, cyclemap allowed). It could attract and save a base of players!
Proposed map rotation:
ut4_cache_b6
ut4_inferno_b3 (no minimap, but if you get ut4_inferno_b3_converted the minimap magically appears also in the orginal version, converted one have some screwed up textures)
ut4_aztek_b2
ut4_dust2_v2
ut4_train_dl1
ut4_dust_a4 (no locations)
There are also:
ut4_cs_assault_b2 ( never played it, gameplay could be bad on bomb mode)
tlw_dust_repack (night lighted version of dust, strange skybox, I'm not sure if people would like it)