Air bags/shocks and the anticipated ride.

I don't think the ride issues your noticing are due to the shocks. Although if they have never been replaced, it may help with the ride as well. I think a hitch like this http://www.trailersaver.com/see-how-it-works/ would likely do more to remove the issues your feeling when towing. If the truck is mostly level with the trailer in tow, I am not sure how bags would make a difference. What I think what your experiencing has more to do with the fifth wheel hitch than the pickup suspension. Your truck has the updated suspension that was implemented in 2011 and remains the same until 2020.