I just use a regular one from Home depot, works fine for $50. Just buy some wrap and keep cardboard around, you can use the wrap or ratchet tie downs to attach it to the dolly. If you want to do it on the cheap and you don't have to deal with grass etc.
http://www.homedepot.com/p/Milwaukee-800-lb-Capacity-D-Handle-Hand-Truck-HD800P/100030159