I currently have a quadrajet on my car from
http://www.guaranteedcarburetors.com/ . I did have to fiddle with the adjustments to get it close to where it's supposed to be. Been running good for about 7 years.
May be a bit of a hike for you but these guys are great
http://www.bowencarburetor.com/. I've had a few over there and they do great work.