Air bags have no detrimental effects when it comes to hauling capacity. Select your bags according to the given application and you will be fine. Look under the rear of most semi trucks and you will see air bags. They are as dependable as any other suspension component when installed & maintained correctly.
As far as rust issues, watch for the cab corners, kick panels and the sheetmetal right above the windshield on the interior of the cab (where the visors mount).
Good Luck and *****in' looking project bro!
