Digital Signage content management - look at Screenly OS running on a couple of Raspberry Pi, very low cost and simple to use system; I have a bunch of them running at my local Community Centre. There is also a paid version of Screenly with additional functionality. Displays - where possible I would go with a Pro Display with in built timer and or the ability to control remotely, look around there are thousands being replaced every day from corporate installs, I have yet to purchase one for any of the Community projects I work on. HDMI Distribution - HD or UHD over LAN would be my preference it is more robust than long HDMI cables, esp. if 'others' get near the kit! Joe