knc1, thanks for the executive summary
The DX is a bit small on area, and I agree, having as much realestate as possible is preferred. I've been eyeballing the latest 13.3" Mobius eInk display, which is the one that the new SONY device uses, however thus far I cannot locate any controller board. Closest I've found is one that was put up for an Indiegogo project by RockTheInk.
Refresh, as you've stated isn't a huge concern, 2~4fps is more than ample.
I've looked at larger mroe traditional displays and the best I've located is a
10.2" soon-to-arrive unit
http://www.pervasivedisplays.com/kits/pdi-demo-kit#tab2 - but as yet no word back from them about pricing or availability.
Another option I was considering was modifying existing LCD panels to improve on the backlights, though that's really a more desperate pitch, and I see companies like BenQ are offering Low Blue light, No Flicker displays for only $599 in 27" size with 2560x resolution.