As far as a NEW quadrajet, as you probably know, GM stopped making them i don't know when, and i think edlebrock stopped making them in either 96 or 03.
You can still check with Edlebrock as i think they still have some even though they don't advertise. There is another place that has NOS quadrajets and i will reveal the source as soon as i re-find it. Also, you can check ebay occasionally.