Rick,
We started out towing our toad with a Stihl brand tow dolly. Best value we found among those available at $1,800. You can spend upwards of $4,500 on some other brands. That being said, we switched to a Blue Ox flat tow system after about 4,000 miles of towing for approximately $2,100 for everything including the toad braking system. The toad tows better, easier hook up and more securely attached to the motorhome.
It does depend on your tow vehicle requirements. However flat towing is our preference after doing it both ways.