The advice I have been given by several suspension professionals:
Best solution for a better ride and handling more (or less) weight is springs. For better ride softer or even stiffer as appropriate to load and driving conditions. Redesigned spring pack (beefier springs/more leaves) for increased weight capacity, again as needed After that airbags for leveling the truck and adjusting the ride, particularly when the vehicle carries highly variable loads (camper on vs camper off).
Shocks are for controlling bounce/rebound.
Consider the consequences of a failed airbag if you take your vehicle off-road and to remote locations. Will it still be drivable even if at much lower speeds? That consideration is particularly important for those who do away with springs and just use airbags (I wouldn't do it but some people do).
I decided to replace the springs on our truck with custom made Deaver Springs to achieve a little bit better ride of the stock springs as well as handle a bit more weight. I also raised the truck 2" front and rear which seems to have made steering a bit less tight.
All of these changes have consequences, some intended and some unintended or unanticipated.
I found the original steering box hd too much play in it after the springs were replaced and the truck was raised so I replaced the steering gear with a Blue Top steering box (a former Red Head employee started the company as a competitor to Rehead). The new steering box has less play than the old worn out steering box (which had just over 400,000 miles on it) but more play than when the OEM steering box was new (and up to around 200,000 miles). I'm not so happy with the Blue Top steering box but it is within spec. It seems raising the truck made it a bit more sensitive to the small amount of steering box play. It is not unsafe but it does not steer like it is running on rails like it did up to about 200,000 miles. Note: I Previously replaced the tie rod ends and king pins.
I hope this is helpful.
Craig