Another possibility would be to leave the stock stator alone, and eeking out more light from for the power you are already using.
A normal filament lamp is using X amount of watts to create both heat and light. The more heat, the less light. The fact that a filament does this creates both a "power hunger" problem and a "melt stuff" problem as you try and crank up the power.
A HID lamp (High Intensity Discharge) takes that same X amount of power and puts out a lot more light and a lot less heat. This solves two problems, you don't have to rewind the stator and you won't melt housings. HID bulbs are also likely to last for the lifetime of the vehicle.
The downside to the HID is cost (though they are getting pretty cheap these days), the fact that it needs an external ballast, and the fact that the ballast can be damaged by excessive on and off cycling in quick succession. Also, a HID needs a large draw of current at startup.
I suspect somebody has worked this out for trail bikes with no batteries. I could think of solutions to all those problems (and can give you a schematic I made for a delay timer so that the bulb wont try and turn on until after the bike has been running for 60 seconds or so to protect the ballast).
Anyway, that's another option... probably close to the same cost as a stator rewind.