Quantum encryption isn’t something quantum computers can even do. It’s not just transforming bits into other bits, it’s about building entirely new security properties based on physical properties of matter.
So, even if it is interesting for end users, they would need dedicated hardware anyway.
I’m not sure what a “music jukebox” is, and how it’s different from a music player, but I would recommend to try mpd. It should work with your collection, although I don’t have personal experience with collections of this size. Some clients might also not have been designed to work with such collections, so probably you’d have to try several.