Welcome to the forum skorp. I know we have a few pure mudders around here somewhere, as I can only really give you snow reports for the next few months. 
there are a couple gear reductions out i found one for my rinny a while back and also seen a rinny with top speed of 25 with 32 silverbacks i believe was the tire it was 54% reduction is what he told me and it shifted just like the normal just different speeds. the popular GR for the rinny is the BRGR. also the final drive gear assy off the big red and I think the pioneer has the same gears as the red but not completely sure.As far as I know there is no gear reduction for any of the Honda SXS. If there was one there would have to be a "shift fix" also through the computer or an electric shift mode/buttons added so it would shift correctly under heavy throttle.
that's the executioner weights? I wish they made a 28 -12rim executioner. found a dirt devil 28-10 12 on the bay last night I think it was 29 lbs. minds is riddled with a lot of tires and weights right now27x10-12 6ply weight: 31.04 OD 26.6
27x12-12 6ply weight 34.34 OD 26.5
28x9x14 6ply weight: 27
28x11x14 6ply weight: 32
I think youd be alright with them they aren't a extremely heavy tire