I went with this case:
http://www.javoedge.com/reflexeshop/...71&pbmId=18384
It just arrived today, so I can't say much about how it affects reading comfort, but the stand works well in portrait or landscape (you might have the cover flap sticking off to the side in landscape). With it in my hands, I'm a little worried about how the faux-leather material will wear, but I'm very happy with the minimal bulk of the case and the firm hold of the magnetic clasp--not difficult to open, but it should stay closed in a bag. Magnets hold the stand flat against the case, too.
An anti-glare screen protector is the only other accessory I'm after, and maybe a 32GB SD card (I have a 16GB now).