I'd get a true 6x17 camera instead of the back. If you're going out specifically for panoramas, less to carry and roll film is VERY convenient for travel. I'd been toying with getting a DaYi as they come with a ground glass attachment which I would find extremely useful for critical framing.

Downside to these cameras is you may need to get new lenses or get used to swapping them out with your Shen.