You will want to get hold of a standard PC power supply.  I had an old 486 PC lying around in a closet that I just removed the supply from.  You will also need some wire.  I used some 18 gauge, solid core, hook up wire from Radio Shack.  It has three colors of wire included with 15' of each.  That was plenty for my immediate requirements.  I also purchased some electrical connectors from Lowes.

Next, I determined that the yellow and black wires were for the 12v (lamps).  I clipped two sets of these, and put a terminal on each.  I wired these to the coin door lamps.  As long as one yellow and one black goes to each lamp, you are fine.

I plugged the power supply into my UPS and everything was ready to go.  The connections aren't wired to the 'Coin up' button on the controller yet, so all the coin door does at this point is light up.  I'll get to the rest at some point in the future.  I also want to secure the power supply to the interior wall of the cabinet so it isn't just stacked on top of the other equipment.