Hello Donna Hucker,
Sounds like a fun project, are they monitors or smart TV’s you are trying to get the Slideshow to play on? Knowing weather or not they are smart TV’s with say a built-in web browser will save you lots of money instead of having to buy A Player for each monitor / TV.
Secondly, do all of these TV’s / Monitors connect to a coax cable weather it is for OTA TV programming or if they use a cable box?