I have ran both a cheap 2 wheeled Sulky and a Wright Velke Sulky one wheel. The cheap one worked good when I wasn't replacing wheel bearings. I switched to the one wheel Velke Sulky and it has worked out very good. I am 225lbs and don't have problems with the front end raising.
I did like the ride of the 2 wheel sulky better wish I would have gotten a Velke X2. It is pretty much what the cheap one tried to copy.