Thanks for the feedback. Yes, I have been imagining the same thing too!

Just need to track down a e-ink display for this sort of fun project. Anyone know of any good ones that would make this easy?

Not really, I've no experience with e-ink displays, if I was to do it, I'd hunt for an older-generation large-size e-book reader and try to hack the firmware a bit.

I have two Kobo readers that are 5+ years old, the small one, I cracked open and found that the Linux OS was on a normal SD card in a normal socket, so I removed it and flashed it to a bigger card, I think one of those should be easy(ish) to hack :)