Hi Stanley, here's a place to start: Aero Ski Manufacturing Co. Inc. 260th St. Municipal Airport Brooten, MN. 56316
Phone 320-346-2285, Troy is the owner and a really nice guy. They build straight and I think he now has a wheel penetrating model. Their M-2000 would be the size you would need for your plane, or if looking for used then Federal 2000's would be about right, also there is a company in Wis. that builds ski's its Name is Trickair http://www.trickair.com/
Hope this helps