The best, would probably be the factory original one, but lots of others carbs would work fine. You can rebuild yours or buy a rebuilt one from Chevs of the 40s, may be the way to go if you want to keep thing original. Also Langdon's stovebolt has more modern carb adaptable to your motor.
I like Langdon's Holley-Weber mainly as it's modern vs 50 years old with worn out body etc etc. Check out his web site
www.stoveboltengineco.com And best of luck
Jim