I have a SuperNOVA and various arcade boards, and I'll tell you, go with the following components:
-Happ Ultimate Joysticks and push buttons - simply, the best on the market. Great feel and durability.
-A quality 120V power supply: Any good brand will do.
-http://www.jrok.com for your convertor...trust me, buy one from this guy (a LOT less trouble and cheaper in the long run)
-*Two* male DB25 connectors. Use these to wire your JAMMA joysticks. Of course, use female connectors for the joystick connectors from the joysticks themselves...wire the buttons from the joystick to the female end, and make sure the male end follows the same wires to the JAMMA harness.
That's all I can really think of off the bat, aside from laminating your joystick's top surface to prevent your hands from chapping. Also, make sure your joysticks are not perfectly planar (make sure there's a slight angle to the top surface, like on an arcade cabinet's control panel).
"Go go gadget go!"