Branch asterisk servers question

I am planning to set up 2 * servers: one in a colocation and another in the main building. There will be 2 T1’s in the colocation and at least 4 FXS and 4 FXO in the main building primarily for back up in case the T1’s goes down. We are a small office that has 50 employees. The colocation will take incoming calls and forward them to the main building where support will handle it.

What would be a good approach for the configuration files on both * servers? Should agent log in be handled in the main office or the colocation? Also, what about queues and music-on-hold? I am thinking that the colocation office should handle all logic, thus requiring a more powerful server, and the main office * server just make sure that the calls are forwarded to the proper extensions of the agent.

I am open for suggestions.