I just dealt with the same problem...I bought new springs from ESPO, and they gave me a FABO discount. I'm very happy with the ride. Mine were made to raise the car 1" higher than stock height. When you take into consideration how much the springs sag in 45+ years it raises the back quite a bit. Cost around $300 including hardware. They have heavy-duty and 'regular' which is what I got. A cheaper option is to add a leaf from the junkyard.
I'm running 14x7 205/70's and they don't scrub inside the fender anymore.
People have differing opinions on air shocks. Most people seem to agree they are ok if you don't overdo the pressure. One concern I hear is that the shock supports are not meant to carry the weight of the car.
Hope this helps....