"Car is street driven with occasional trips to the track, would a Q-Jet work fairly well in this application? If so does anyone other than JET and Edelbrock make them?"
a Q-Jet would be perfect for that but you do need a matching manifold. you should be looking for an Edelbrock RPM Q-Jet #1910 rated 850CFM, should be good to 600HP. I think they stopped selling them in 2005 so it would have to be used, I seriously doubt there are any NOS left in the world.
For a Rochester Quadrajet you would want 1976 & newer M4ME large size, 800CFM, the smaller 750CFM would likely run out of idle adjustment.
I think JET only rebuilds them
Have fun with the hunt.