This is my solution too. My server with private data is only accessible via my LAN. I'm home often enough that syncing isn't a problem. I kind of treat it like

This is my solution too. My server with private data is only accessible via my LAN. I'm home often enough that syncing isn't a problem. I kind of treat it like the old Palm desktop, where you had to sync regularly by USB. The nice thing is that the sync is automatic in this case. I know that kind of punctuated syncing wouldn't work for everyone, but it works for me. My public server has a couple of ports open to the internet, but SSH, SFTP, etc., are only accessible on the LAN with access by key (no passwords). It does things like XMPP (hashed passwords, no locally-stored chat data), public websites, and the like.