If you like the BFG AT KO tires, but not thrilled about the price, then look up the General Grabber AT2. It is a very similar tread design to the BFG for much less money. It comes in just about any size you pick and for maximum towing, get it in the LT metric. The load range is higher than the P metric. The trade-off: P metric sizes are cheaper than LT metric.
I have heard that the BFG's tend to wear down quick for the first 50%, then slowly after that. Not personal experience, just what I've been told by a few friends running them.
A good site to look for pricing as well as real-life reviews by people using the tires is Tire Rack - Your performance experts for tires and wheels. Haven't read anything other than good reviews for the General Grabber AT2. It's one of the tires I'm considering for the future.
Good luck finding the right tire for the truck!