Have a look at the Entourage Edge, it might fit your needs. If not for the word-processing pretty much any e-ink device would fit your needs. The Entourage Edge has a double screen, (LCD on one side, e-ink on the other), 9.7 inches:
https://wiki.mobileread.com/wiki/EnTourage_eDGe
There is also a 7 inch version:
http://www.entourageedge.com/devices/pocketedge.html
The website states that you can create Word, Power Point and Excel documents using the device.