I found an excellent case at Chapters. It's a vinyl zip up paperback book protector for travellers (I think it's called The Book Tote).
It has a large, thick paperback size, piece of foam on the inside pretending to be a book. I just cut the foam in half with a bread knife and tucked each half under the front and back inside flaps of the case. The reader, with it's cover, fits quite nicely in its new well padded vinyl zipup case.
I suppose I could cut up some rectagles of plastic and slid them behind the foam if I wanted to add more protection.
It was six bucks, and works wonderfully.