Nobody in their right mind would build a kit for a Rokon Trailbreaker.
They still make them, and the price reflects the specialized gear boxes to provide 2 wheel drive. You might keep an eye on Craigslist, sometimes older ones get sold for far less than they are worth. The WB 820 2 stroke is still in production & parts are available.
The rising popularity of fat tire bikes on the other hand may give you a way to get close to that bike for winter weather. 2 wheel drive with electrics would be much easier.
The very high price of lightweight batteries will make it an expensive project. It is unlikely that anyone would kit such a bike, with single digit monthly sales.
Just for fun, here is a 2wd daily driver. Corbin does not own a car, and rides every where on it:
Corbin on Mullholand
And here is a 10kw MTB - swap that drive in to a Moonlander...