#1 - what's your budget?
Small block/big block?
Is all the suspension original?
Are you looking for a smooth ride or a tight suspension or ?
I am now using the KYB GR-2's which are affordable (~$100/4), I have paired them up with 1" drop 560 coils in the front and 4 1/2 mideye leafs in the rear and they give a nice ride without too much lean, kind of a comprimise. Wife and 10yr old (back seat) have never complained about the ride.
The KYB Gas-A-Justs are stiffer, too stiff for some. Going up in price I've read great posts about Bilsteins and Koni's but they're a bit $$$ for a daily driver that won't see track time.
Jon
I have the KYB gas adjust on mine and like it. The GR2 will not be as stiff, so it depends what you want the car to do. I like KYB because it is reasonably priced. Its not cheap, but its not expensive either. I think they are a good quality schock.