Hi HappySpillmore,
They are basically the same bike but with little variations. However there are three generations of LF200-III bikes, the latest is from American Lifan only just like the LF200-B.
The first two generation were offered by American Lifan and interent dealers but they were not exact, there were some small differences, like exhaust canisters for example.
The main difference is service and support which American Lifan offers with all of their bikes.
If you buy a bike off the net you are basically the service man for that bike and parts are also hard to come by.
I hope our site helps you with your mods, Chinariders is a great place for information but they are mainly concerned with the dual sport bikes where we, lifan-moto.com, are mainly concerned with the sport bikes.
Both places offer a great sense of community.
Almon