I am looking at Air Lift Load Lifter 5000 Ultimate Plus for my 2015.5 GMC 2500HD to haul a 5th wheel toy hauler that will weigh around 13000 lbs dry. Are these kits any good? I like the fact that this kit has stainless hardware for us northern guys. I do have the B&W turnover hitch in the bed I need to miss with air bag hardware though.