I used the swivel wheel sulky from these guys:
Used it with a 60 turf tracer with a 20hp Kawasaki. Was a great sulky, quite heavy though but had convenient grease fittings and was very durable. Loved backing up with it a lot easier than pivot arm sulkies. If your mower has at least a 17-18 hp engine it should pull your weight being a hydro drive as well IMO.