I'm just in the process upgrading my Baywatch with an LCD screen in the backbox. This will use a so-called PUPPack. This is a pack of videos and triggers. Depending on the trigger, a video will be started, stopped, lopped, ...
More about PUPPacks here:
https://www.nailbuster.com/wikipinup/doku.php?id=pup_capture
As the player hardware I'll use a simple Raspberry Pi. It can boot quite fast, is inexpensive and small.
The current software can be found here:
https://github.com/pinballpower/pipup
WARNING: At this stage the software is only rudimentary and buggy. It's not ready for end users, but for developers who might even be interested in contributions.
Once my new Baywatch backbox is ready (hopefully in 4-6 weeks), I'll post some pictures.