Not to be outdone by Hook, I bought myself a Thinkpad tablet folio keyboard from a 2012 thinkpad android tablet on ebay. The selling point for me is thinkpad + usb interface in a fairly contained package. As a bonus, it's a rare thinkpad keyboard with optical trackpoint, which no one else seems to like but I love. I plan to use some sugru to mount something inside of it for eventual outdoor typing for my own less restrictive, if also less cool, eink word processor. The lack of a good hinge is the biggest downside to me, but it was only $20. As to what eink device would go inside of it, I'll probably be looking for a bargain as much as anything. It's not something I plan to use all the time, just computing in sunshine. Last year I remember seeing a yotaphone 2 go on sale for about $120, I drooled for a moment remembering when it first come out 4 or 5 years earlier at $900 msrp, but couldn't think of a use for the aging hardware and passed. Oh how I wish I hadn't. That price is practically the cost of the tiny eink display, and android ereaders with crappier chipsets (albeit, with bigger, newer screens as well) sell for far more. Not a great phone, but would be a pretty decent word processor and would probably even get better battery life than all but the most massive of ereaders I've looked at. My old onyx boox afterglow 2 had horrendous battery life owing to the manufacturer's incompetence, used as much juice idling as it did in active use. I bet the phone would idle better. In any case, options range from about $200 to $800 (the onyx boox max 2 is pretty cool, 13" android tablet but can also function as a display via hdmi for anything, including windows), but none are quite a match for me, so I'm just keeping my eyes open. Raspberry pi, phones, anything is possible. All told, I now have 5 thinkpad keyboards. 3 attachments for my helix 2 (2 pro keyboards with extra battery+hinge+trackpoint, 1 normal w/o those but with a stylus silo), a thinkpad tablet 2 bluetooth board that I used with my little dell venue 8 pro and first introduced me to the optical trackpoint, and now this thinkpad tablet folio. I prefer to think of myself as a perfectly sane collector, though a psychiatrist might have another perspective. Good thing I can't afford a psychiatrist!