Contacting James is never an ASAP type situation. Last couple times I have bought from him it was always several days before he responded. But, he is a hell of a guy to work with and will bend over backwards for you. I would personally never considering buying a JROK from anyone reselling them but him.
What kind of questions do have about hooking it up to the SuperNOVA? It isn't going to be a plug in type affair. At the very least you are going to have to solder the wires for the power (+5 volts and ground) and the video wires (Red, Green, Blue, Sync and ground). Once you identify which is which, hooking it up should be straight forward.
Arcade4Home has a pinout for the 8 pin din on the outside of the Nova. That 8 pin din provides both S-video and straight RGB out. Simply track down the wiring to that connector from the backside to hook up the JROK internally and then find the +5 volt rail coming off the power supply.