If the original runs great, leave it be (unlikely).
Most folks like the convenience of the auto (electric) choke, but it's finicky to set perfectly and generally ends up on the rich side to run well under most circumstances. I too personally like the manual choke since you only use what you need, which shouldn't be much unless its really cold (not Hawaii). I've run many carbs without a choke and had no issue other than having to hold it for a bit after pumping to fire it up. Manual choke is the best of both worlds IMO.
Weber offers a conversion kit for auto choke carbs, and its cheap. An auto choke carb can be converted to manual but a manual cannot be converted to an auto. I would personally sell or give away the used who knows what carbs and buy a genuine Spanish Redline Weber if you want your Brat to be reliable and fun to drive... the cheap stuff is Chinese knock off and its absolute garbage; it will not last. A quality carburetor is worth every bit of $3-400; it is your entire fuel/air management system and that is dirt cheap.
K 730 or K 730-M
K