OpenVPN actually works very well with compression: used it for 2 years to synchronize databases between 2 sites in India and one on the US and the compression cut the sync time nearly in half. It was pretty much fire-and-forget: I think I only looked at it twice in the 2 years after I set it up, both times to replace certs. I'd use that over an ssh tunnel, if only because you wouldn't need the autossh tricks.