I doubt you'll come across any airplane wheel skis (what it sound like what your looking for) that people are willing to part with. It sounds like a job for a homemade/cobbled up arrangement, as since they don't have to be AIRWORTHY just snow and ground worthy.... I'd bet a walk through of a (pick your favorite chain) large sporting goods store will show a lot of possibilities that can be modified with Harbor Freight/cheap wheels. Check out the devices the ice fisherpersons use to drag their beer out to their holes, and other ready made, mass produced, cheap, snow sliders. It may take a light gauge steel frame (1" square tubing), bolted onto a not made for that purpose sled of some kind, to distribute the wheel loads to the sled. I do things like this for my local Ski Patrol often, a good cause. If you were local, I'd have something that'd work cobbled together in a day or so, for less then $100.00. guaranteed. I know my local patrol have fiberglas rescue sleds (that I have not had the pleasure of seeing real close up) that would seem to be plenty stout enough to take a pair of wheels that stick down just enough to roll on ground but not cause too much snow drag. "Piece of cake", says this snowboarding, ski plane pilot!