Bill Pierce
Well-known
I'm sure this is one of many threads, but in case you haven't come across the information, the M8 has new firmware that will allow "discreet" advance (no cocking noise until you trigger it) advance.
http://en.leica-camera.com/service/downloads/rangefinder_cameras/m8/
http://en.leica-camera.com/service/downloads/rangefinder_cameras/m8/