Beastmaster in most other MMOs have been problematic for DPS in raids. Since the pet is a good source of your damage, and Raids have more AoE then just solo content, so you would spend about a third (or less, not really sure) of your time making sure your pet is up.
Here is something I came up with, it isn't a pure DPS build, but I think with Warlord you would be more beneficial to the raid for buffs and what not.
Beastmaster(35)/Warlord(20)/Champion(11)