This is what I did: The front wheel I built myself using an Alex DX32 bicycle rim, 14 ga spokes, and a Shimano disc brake hub. The rear wheel I had built for me by The Wheelmaster in Auburn, Washington. The rear uses the stock Puch hub, an Alex rim, and custom made 9 ga spokes. The tires are Sava 2.25x16 MC2's I bought from Tomos.
The result is lighter, stronger wheels with better brakes in front.