I think there should only be 1 version of each map on the server. Since magma v2 and 67th way(some other version) have been added, they are getting played WAAAAY too often. This causes repeat maps to play, and the map with more than 1 version has more chance of being chosen for random. Also, if 67th way v1 is locked, we can just vote for 67th way v2. I hate playing the same map 2 rounds in a row, even if they are varied slightly. Removing these maps allows the inclusion of more maps that are suggested by the community. Perhaps you could start a forum wide poll to decide which version of each map to keep or have.
I think there should be one voting option for each map; one for magma and one for 67th. Then, if the map is selected, one of the two versions are chosen at random.