I'm not wild about roman shades that sit outside the window frame, but in office, maybe we pair blackout honeycombs with roman blinds like this? Would provide great light and draft blockage...
If I were to go with a patterned fabric, I like something with large medallions like this. It still may be a little busy for me, but something along these lines. I have yet to come across any though.
http://www.akdo.com/products_list.asp?mcatid=11&catid=62&viewall=true