Did you decide if you wanted to go with an LT or P rated tire ???
Some others to consider :
Nitto Terra Grappler
BFG AT's
Michelin AT2
Bridgestone Revo2
Goodyear Wrangler Silent Armor AT
Firestone Destination AT (great value,nice tire,nice look)
Nokian
The heavier you tire the more gas you will suck. The more aggressive also will suck more gas . I personally would stay with a P rated tire , better ride , lighter , no not as tough , but I've never had a problem. 99% of peoples driving is on road / snow / rain...ect... Because of these trucks and their 4x4 system I would also replace my space to the same size.
Also some tire places will NOT mount a larger tire , so beware of that.
The only 2 I've owned above are the BFG AT (15 sets of them) and 2 sets of Revos. My next tire will not be either one of these 2 .