The easy answer on the belt is that you can get any size belt imaginable from the auto-parts store. The m104 and m103 use the same belt. You can get the belt for the m103 that was not equipped with a smog pump in the U.S.
The pump has to be removed.
Repl. the bearing is not as easy as it sounds. The bearing is hard to come by. I have only heard of a couple people selling it and it is pretty expensive. Like 60-90 dollars or more.