towing near max weight. advice?

Do your self a favor. What is the gvwr of the trailer you want? Figure the tongue will weigh 13 percent of the loaded gvwr and do the math. What is your hitch rating for max tongue weight (usually around 1100 on 1/2 tons). Also figure tongue weight, weight of all passengers, weight of hitch, firewood, bikes, dogs or whatever you load in the truck. Add it up and this will tell you how much payload you have to work with.
I am only speaking from experience of overloading a 1/2 myself once and it was not a safe or pleasurable Towing experience.