Hello Fred,
In addition to Gene's recommendations.....
It is fairly difficult to find a "non-gas" shock these days.
Seems most of the major mfgs have converted to gas-type shocks.
There are two different types of gas shocks - low pressure and high pressure. We will save the high pressure versions for the high performance guys as we are not interested in the ride quality of these.
From personal experience, you may wish to check out Monroe and the Monroe-matic shock. It is a very good quality shock, although it is a low pressure type. I have installed several of these with positive feedback from customers which wanted to retain the "old car" feel.
I call that compliant ride quality and they also seem to work very well with bias-belted tires.
You may want to check out this link
http://www.rockauto.com/catalog/raframecatalog.phpThe Monroe-matic Part Number Front 32066 and Rear Part Number 33049.
Be forewarned that Monroe will make the marketing comment that the Sensa-trac model is OE ride quality. Yes it is - if you are driving a 1975 or newer Chevrolet and we all know those had radials and a quite different suspension from the 55-57 models.
I hope that helps with your decisions.