If you are looking for B&L parts then probably the only place that you will find them is at B&L directly. Since you`re looking for addons like a drive motor, the best thing is to take the mount to a top of the line telescope store and have them find something that will hopefully fit. If the mount is a Vixen or a copy then you will probably find the motor that fits. The odds are that you aren`t going to find any parts for the scope in the stores or other places because of the fact that B&L for one isn`t a very good maker of telescope systems. Thier stuff is more in the way of a "department store" telescope quality which is a way of saying it`s junk more designed to frustrate people out of astronomy than to lead them into it.
Many people in the hobby are more the handyman types that are able to build or otherwise "invent" the necessary stuff rather than to buy a few pieces and then wonder why the pictures don`t match the view through the EP.