I had a set of the Cooper A/T3's, and was very happy wth them!!! Enough traction during some pretty heavy snow storms in Northern Michigan snowmobiling, even traveling up to "the bush" in the Soo, Ontario, Canada area for snowmobiling!!! Just haven't replaced the stock goodyears on our current truck yet. As we all know tire prices are ridiculous, so haven't replaced them YET!!!! Will be either the A/T3's, Toyo's, or the BFG AT's when I do....
They also have a 50k or 55k mi tread warranty, for an AT LT tire!!!
I have also had the BFG AT's. The A/T3's did just as well from what I recall.
Buddy has a set of the Toyo Open Country AT2 (I think it is) Extreme in his Ram Megaca he is very happy with them so far.
Not sure how either of those tire's will do towing that heavy, sorry.
Good luck deciding!!!