I built an 11x14 and I have the back off a Deardorff 11x14. It is a very nice back. The rest of the camera is not too bad either. Yes you can get film in 11x14, I get mine from Freestyle and I DO backpack with mine. I do 11x14 carbon transfer prints and boy is that big negative wonderful. You really do forget about the weight of the system out in the field when you see the negatives. Someone should pick that up.
I have been thinking about building a large format camera. Where did you find directions for an 11x14 camera???