there is one here that opens like a book.
perhaps you can find one at tipnut
There is one here.
I have made several of these. I did add a different type of handle (sewn directly into the short side of it rather than the top side with d-rings).
I have a first generation Kindle and love it.
Big caution on any cover is to help prevent crushing the screen... it really does not take much.
Good luck with your quest.