If you do buy one I suggest adding locking washers to every bolt inside because they don't have them as standard and over time all will work lose. Do it before you install the motor because in a few months time the top bracket that is forced onto the main shaft will be too tight and corroded to remove which makes it impossible to remove the upper casing.
I would advise you to add an additional elevation support bolt on the other side, you can use the internal motor fixing bolts to hold it in place. Without it there is too much rotational stress on the casing when it is windy and it will weaken the low grade aluminium casing.