It's perfectly possable. There will be some work involved, such as swapping over the CCD ignition stuff from under the seat, but it can be done. I would suggest if you plan to go that far though that you get the engine from an Urban Express, as that gives you a variator, an electric starter, etc as well. It will mean even more electrical work (swapping over 12v parts in place of your 6) but it'll give you more bang for your buck.
If I ever find the parts to convert my own, I'll post a walkthrough on how I did it.