RANS S-7 Courier
Because of its light weight the Courier makes an excellent ski plane. There have been many successful installations using straight, wheel penetration and retractable types.
In my area, we usually have less than a foot of snow and I can get by with a small plastic snowmobile runner ski with a metal frame. Most people feel wheel penetration skiis have the most drag. The Datum retractable ski has many satisfied customers including several on the Courier.