Sync files between head office and branch office

Hi Guys,

I'm looking for suggestions on the best way to give a branch office, with fairly poor bandwidth, access to files stored on our head office OES servers.

We've been using rsync with some success, but both head office and branch office may modify the files, so we're getting collisions.  Unison works ok, for two way sync, but again, we're getting collisions.

I've even toyed with the idea of putting Filr on a Windows server, at the branch office, and sharing the filr folder off that.  Could I do that with an OES server, and the Filr linux client?

Is there an OES recommended way of doing this?

Thanks for any suggestions