Sorry I don't know about cases - I think some of the threads in this forum has mentioned them. Example:
https://www.mobileread.com/forums/sho...d.php?t=155420
When looking at cases designed for other devices, remember to consider thickness as well as length & width. And if it's a book-style cover that you always leave on, ports and buttons might be hidden.
Chapters has some book-style covers on their website.