I got my 5200 from Stovebolt. I wanted something with a manual choke, but he didn't have any so this is what I got. (Still might switch to manual, kits are avail.)
According to his instruction sheet sent with the carb., "Newer versions of this carb had a fully electric choke, which can be installed on older carbs."
Tom at Stovebolt should be able to hook you up with one.
As far as my elect. choke, I ran off the back of the ign. switch with a 10a inline fuse. I plan on borrowing a DC ampmeter to check, but so far so good.