Synchronization from multiple computers

Hey everyone,

we are a couple of researchers using DevonThink to organize our stuff. However, we need our boss to have access to all our data whenever he wishes it.
Before using DevonThink we just used normal folder structure in MacOSX and then shared using DropBox.
What is the best way to synchronize many DevonThink databases on multiple computers to my boss´ computer? We are all on the same local network.
DropBox could still be one possibility, but the databases are all getting larger and larger with time, and I can understand that there are some problems using DropBox if two users open the same database simultaneously.

I would really appreciate your help!

Thanks a lot.