Hey Dean,
We are now pulling a short 5th wheel (the boss's idea) but before this had a Lance 855s then an Eagle Cap 850. Both very heavy but the truck in our signature handled them well.
We went with OEM steel wheels and mounted 4 Nitto Dura Grappler highway tread 285/75-17 tires rated at 3970# each. Timbrens on the rear axle.
We traveled all over the northeast US and Canadian Maritimes and never had a problem.
Good luck with your decision. You have a good truck for a TC once you beef up the tires and suspension.
Weight police, take the day off.