I think air bags can add stability as long you don't put too much air in them. However, the only way to know what you should add is to try it. The spring shop probably knows more about what to do to the springs than any of us.
🙂 I've read here that lots of people really like their aftermarket springs made just for them.
Don't forget about your tires as you are upgrading though.
'10 Ford F-450, 6.4, 4.30, 4x4, 14,500 GVWR, '06 Host Rainer 950 DS, Torklift Talon tiedowns, Glow Steps, and Fastguns. Bilstein 4600s, Firestone Bags, Toyo M655 Gs, Curt front hitch, Energy Suspension bump stops.
NRA Life Member, CCA Life Member