What suspension upgrades i should consider for my truck?

also have a new dually but another brand. I keep thinking I might want to do something, but with 4500 lb camper plus tong weight of trailer its riding level, so maybe I will just leave suspension alone for a while.

But I do need to add weight distribution hitch because my 34" 2.5" curt hitch extension is rated at 450 lbs tong weight without weight distribution and 600 lbs with.