Hi Thomas,
I have exactly the same model (16S/B-GS) and been fashioning new power supplies for it the past couple of weeks.
As regards motors, Arri themselves produced the Variable Speed Motor (probably the most common one still in use), running of 8.4 V battery power for 4-48 fps, and then two types of constant speed motors, known as Governor Controlled Motors, one for 24 fps, one for 25 fps. They also take 8.4 V, although technically, you could power them with 6V car batteries at the time too, for around 18 fps.
For the B-GS models in particular, Arri later produced a new mo