I remember about 32GB is the a maximum for a older system. I got the trouble in the past, when I tried to add a bigger harddisk on a old 700mhz system.
You can maybe add a usb interface and use a ektern harddrive that avoid the limit?
I guess mine own Arcade Music Box jukebox software can been used with just a joystick + 2 buttons (Like Doscab, Wincab). It should run in a lowend system (like a 64mb and 233mhz, wich should been a good choise to run most software out here).
Doscab is a great jukebox software, that run happy on a very lowend system, and it dosent even need a touch screen or using a mouse to control. It can been controlled by a joystick and a few buttons too, or using a keypad only. You do not even need a Windows Lincense to run this one....
There are other great software (yes, Freebox is a VERY great software too), that can operate with buttons only, but please chooise your best software, and good luck to your project :-).