Buying new truck: ? about gears and cab configuration

My 4wd short bed extended cab Ford was stable towing my toy hauler or enclosed trailer (both were tag pulls) at over 19K lbs GCW, so I believe the wheel base is sufficient. Mine did have the heaviest suspension options and the diesel engine which brought it to about 7250 lbs empty GVW. 4500 lbs was on the front axle, so unloading a little weight from the front did not hurt handling - I'm not sure if the gasser would unload much with a fifth wheel.