I don't think the Magic Controller would be necessary.
I may have interpreted the description wrong, but I got the impression it may come with it's own controller as they state it "works with the thumb type 5k Pot throttle only".
Plus there is no mention of a brushless controller being required, they purely state that "you will also need to purchase a thumb throttle".
I expect it has a built in controller, which would explain why it is only suitable for counter clockwise use.
As most petrol (gas) engines are clockwise rotation, it would not be quite so straightforward to convert.
Alan