There are a lot of products out there as I’m sure you are well aware. We recently purchased a NIX, 12″ inch screen which is inexpensive and suits our needs. You create your own slide show on a thumb drive and plug it in so you can have as many programs as you want.
My only disappointment with it is that the settings for the slide show allow for three seconds, which is kind of fast, or 15 seconds, which seems an eternity at times. You can of course manually go through the pictures, but an automatic setting for 6-8 seconds would be much better.