Another one to consider is the Yokohama Parada Spec-X. I have them in a 305/50R20, and I've been very happy with them. Not just traction, but rain, noise, and wear as well.
Granted I've got a CCSB 4x4 LB7, it's driven 99.9% of the time in 2-wheel drive. I've got the overload and 2nd leaf...