Mark, you clearly overestimate my geekiness. I'm trying as hard as possible to Macguyver a solution, not actually, you know, develop something quite so sophisticated from scratch.

So far here's what I'm looking at:

Canvas Photo Printing (best prices and most versatile sizing I've found): http://www.uprinting.com/index.php?main_page=confirm_digital_specs&type=order

Decent prices on Somfy motors and roller parts: http://www.av-outlet.com/index.html?target=dept_418.html&lang=en-us


EDIT. Ok, looks like I may go with a Somfy motor that features integrated IR sensor. This would probably require the least amount of hacking because I'd be doing only assembly instead of having to first tear down something that's already put together in a specific configuration (like a pre-built window shade).