Just picked up a 642 today. The guy at the store showed me a Galco Side Snap Scabbardd. He said it's his favorite for the J frame. Very comfortable, hides pretty well, can be removed without removing the belt.
I was wearing shorts so I didn't try it.
Also while looking at the Galco site I see the speed paddle holster.
Does anyone have any experience or advice as to whether either of these are good for me and my 642 ?