I do something similar, though I use git-annex / assistant to manage the files. It can have remote data repositories using rsync with transparent encryption (using GPG keys).
I also have a bigger drive at home mounted on a raspberry, which stores both the important files (as a second backup) and a lot of unimportant crap.
I just need to setup a synchronization/encryption schedule. I'm thinking rsync remotely to the server. Not sure on encryption yet.
I'm also using the servers as development and minor hosting for myself. It's practically a free storage solution?
Am I crazy?