As far a dedicated server balancing, all I am currently doing is using a round-robin algorithm to pick the next world server (hardware device) to spin up a map instance on. So if it sees you have three world servers (hardware devices) and two of them are running 5 map instances, but one is running 4 map instances, then the next map instance to spin up will be on the one with the least number of currently running map instances.
If you have any other specific needs or something you are looking for, let me know.