If you do end up getting a larger truck, I'd shop by GCWR if you're going to pull something big. Everybody drives around overweight anyway but that's your call. *cough* been there, done that. *cough*
By the book, my truck has a GCWR of 20,000#. The truck itself is ~7100# empty. Add four guys and gear so say 1000# and lets me pull 11,900#. Now say I add an 45 gallon auxiliary tank at 400# (fuel 315, tank 85), four quads @ 1600#, everything just whittles away at your capacity.
truck 7100 12900 remaining payload
gear/guys 1000 11900
aux fuel (dsl) 400 11500
four quads 1600 9900