Check out this product:

http://www.thezephir.com/

It can controll most audio/video components. While it wont help in ripping disks it will allow you to build a custom interface to controll the changer from your mac. Add a firewire or PCI video capture bridge and you can watch movies and rip the DVDs on your mac, all without altering the DVD jukebox in any way.
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PB G4 15" 1.2ghz - Pismo G3 400 mhz - iBook G3 500 "Jukebox"
"SawSmurf" G4 500 - Quicksilver G4 Dual 1ghz modding...