I've tried a single carbide ski twice and each time it washed out really bad on turns. It also made getting on and off the bike harder. I didn't find any advantage at all to a single runner at all.
So with the info posted the dual skag will be the overall ticket for icey road and powder use ???, any one going to build there own out of cromoly tubing and grade 5 bolts or exhaust studs , I would think tempering by heating up than quenching in oil instead of water should work best .