1957 rear suspension help

[Trucknut57]

I have been searching this site and many others for help with an issue I have.

I use my truck for everything, shows, work, towing, hauling, etc... I am running a stock axle with a power rack and pinion up front and a 72' Camaro rear axle with TCI rear leaf kit. (axle over leaf).

Problem is, the rear leaf kit rides great without a load or trailer but is a little soft for towing or hauling. I would like to keep the setup I currently have but help it out with adding either an air bag set or air shocks for when I need to haul or tow.

Since I don't know much about either air bags or air shocks, I need some help.

Which one should I go with? Please give me some pro's and con's if you have any.

Thanks.