Hi Dave, if I remember right your in the Sumner/Bonney Lake area? You might check with Bob Everett at Evergreen Muscle Car in Auburn, just West over the 15th Street Exit from 167. He can get you anything you would want (stock to modified) and get you the right unit (if you go for a new one) at a resonable price. (Tell him Brett sent you)
How's the car coming along anyway? Hope your making progress... sounds like it. There is the Western Washington Firebird club All Pontiac Show coming up on July 30th at the Everett Mall... just FYI. Great way to see lots of Firebirds for reference, and to do some networking for parts and info!