WOW!!!!
I have no idea, just design it as you need it and don't be in a hurry, details details details.
plan it out on paper get with some buddies who can help fab stuff and have fun with it.
The only motorcycle motor I've ever seen in a cart was a H-D Sportser motor, complete with foot clutch, chrome tipped dual exhaust and 6 pass seating and a full cage LOL
I know of no kits or quick hook ups, you can do it because you've already started planning I'll bet
keep us posted with pics
It may be easier to offer assistance if we can see the " DEMON IN THE ROUGH"