Using some of that crazy disk space for backups

I’ve been a DH customer for over a year now, and I got that sweet deal where we get 200 GB of disk space. I’d like to use a bit of that space to automatically back up a few files on my Mac using ChronoSync.

I was going to create an encrypted disk image and put it in a WebDAV folder, but Disk Utility seemed to think that I can only create a 9.7 GB image in the WebDAV folder… Is this a problem with WebDAV in general, or Dreamhost in particular? Does anyone have any recommendations for a better way to do this?