Cart before the Horse? Just got 1st 5er... Need truck wisdom

You are correct on bed length versus hitch needs. Your rig loaded will weigh about the same as mine= 1ton single or dual rear wheel diesel with exhaust brake. Upon purchase check the dot date codes on the trailer tires if they are originals they will need to be replaced with lt rated tires (ignore the st versus lt debate... you need lt or 17.5 to avoid issues).