They are very loud, and quite large. If you look for one, make sure you get it with the connector that goes between the winder and the camera. They can be hard to find, and without the connector, the winder is useless. (as the eBay listing indicates).
By the way, it is rumoured that you can use one of these winders on the 645e as well. Mamiya never advertised that.
I don't know whether the thumb operated rapid winder for the 645e will work on the 1000s.
By the way, Q.G., don't you mean that the left-handed grips are "sinister"?
Personally I really, really like left-handed grips. I am, however, very left-handed.