Manual - less expensive, works as well as the knowledge of the operator.
Automatic - much more expensive, never works well, but works after a fashion until it quits working. :rolleyes: This is true for a moron or a PHd. :p
For many years the two most expensive cars in the world (Ferrari - sports, Rolls-Royce - luxury) were equiped with manual chokes for performance and reliability.
If there are kits to convert a manual choke carburetor to automatic choke, I am unaware of them. Believe one would be required to switch to an autochoke carburetor.
Jon.