[MrBasse]

Andymark wheels should work well, another option is a wheelchair tire that will mount on standard utility wheels you can buy at harbor freight/menards/homedepot/etc. We get ours from a medical supplier called Airway Oxygen, but they are pricey. We were able to work out a partial donation though.

Something like this: http://www.1800wheelchair.com/produc...am-filled-tire

You could also try the non-marring wheel that Harbor Freight carries. $8

http://m.harborfreight.com/8-inch-no...obile_redirect