I may be late jumping in, but would you consider an enTourage eDGe? I think there are still some for sale on ebay at a good price ($169). The e-ink screen is 9.7" and is attached (opens like a large book, or a sideways laptop) to an Android LCD that is 10.1". I use mine as my primary reader and it is quite marvelous!
There are some problems with some units, and the company is out of business, but there is a strong and helpful community here on MobileRead. I think it hits all of your requirements, including pdf support (on either screen).
Browse here and see what you think:
https://www.mobileread.com/forums/forumdisplay.php?f=218
Hope you enjoy whatever you decide to get!!