Since I last visited, I received a Purple Floral MoKo Amazon Kindle Voyage Case - Ultra Slim Lightweight Smart-shell Stand Cover Case
http://www.amazon.com/MoKo-Amazon-Ki...dp/B00NPU3AKY/ and after using a sleeve for the last two months, it is definitely better to be using a cover - and happy to have a satisfactory book-style cover at that.
I was also looking at the book-style MoKo Amazon Kindle Voyage Case - Standing Origami Slim Shell Case
http://www.amazon.com/MoKo-Amazon-Ki...dp/B00H7TVBJG/ - 18.99/Prime but only comes in black right now. Like to see some reviews.
Sadly they are pleather but not terribly expensive and solves the immediate issue of having a cover at least. The sleep/wake function works great.