Hmm, I wonder how much of this could be recreated with a Remarkable 2 or equivalent tablet. Build a nice decorative enclosure with the charging port embedded in the frame, it has wifi out of the box, and you can change the screensaver with scp when it's awake. Perhaps just set a cron job to grab the latest image every 24 hours from a designated url? Obviously much smaller, but you get a tablet out of the deal too, at 10-15% of the cost.