I have a suggestion. It will make the Kindle larger but it should give pretty good protection. It is an M-Edge Executive case. It's pretty well padded. The purple one i on sale for just under $12.
http://www.medgestore.com/shop/kindl...ite1/executive
The problem with a lot of cases is they can be easily wedged open and then the screen is easy to get at to damage. This one has a strap to keep the cover closed and it's not easy at all to accidentally have the strap removed and the cover opened.