they are 12 1/2 long by 2 1/2 wide. Have never had a problem with them re any type of snow. The only problem I have had with them is the wearing out of the metal, as I fly often just on bare ice and that really wears them off. I pop riveted a brass piece on the bottom and also an L angle aluminum bar on the top so that they do not bed any more. As the ski wore they started to bend very easily.
Re the G26 on floats, I am wondering if that will be enough power, as the suction of the floats. on snow or ice that is not a problem. I have a FPE 40 cc and in deep snow I can tell you it really comes in handy, as the skis are at least an inch under, so you really need the power. If you can get a bigger ski it would even be better.