You know,,, this car of mine never had a hop problem.
I think who ever setup the rear years ago really knew what they were doing.
I installed the bags at the same time I removed the ladder bars, boxed the arms (all four) and installed new polly bushing.
I do think that the air bags are your best and cheapest solution.
You may have to play with the air pressure to get it right.
Make sure you plumb then independently so you can put more air in the passenger side. ,,dq