Just one note to add on the thread: at the quilt store where I bought my machine--I bought a Babylock, but they sell primarily Pfaffs--they hold many many classes and said they do not allow cotton thread on their machines because it's too linty. I'd never head that before and to be honest, the poly I use seems just as linty. I only use poly now because when I got my machine it was a floor model and in need of a tune up so was very picky and only worked well with poly thread. Now that it's turned, I know it'd take any thread. I've purchased so much poly--that's what'll be in my quilts for a long time to come.
Flannel sheets for a back--now that sounds intriguing. I never would have thought of that. If I see some great patterns, I may give it a try. Thanks for the idea!