I like flounder33 have both Knight and MMP and the Knight are the thickest. The knight also has a different base cup, the MMP is stepped and the knight is a smooth taper.
My go to sabot is the Harvester short black, I buy them buy the case from Graf and sons, for $4.79 for 50 they have the best shipping price out there. for your .430 experiments try the green harvester. You can always paper wrap or knurl you bullets to get them tight.
Ken