Just like Dave and John said, if you want to do it for yourself, it would be a cool project. I don't think the resale would be worth it.
If you are going to use a pc, there are interface boards that you can use the original buttons and wire to the pc. Here is one controller that should do it..
http://www.ultimarc.com/ipac1.htmlBuid your own Arcade has an excellent section on BYO jukes with everything from software to touchscreen stuff and I'm sure there are other interface options for the buttons as well.
http://forum.arcadecontrols.com/ I played around with some of the juke software awhile ago and its pretty cool. I never got around to building anything with it though.