I'd be happily on this too.... sounds like a dream for me! but I dot have a silent mode, and, which is more sufficient, I dont have a proper 90mm, 135mm lens. recently I tried to do this (shooting with a non-hidden 'non-working' camera) with 16-35, it does the job (cause its autofocus works like crazy!) but.... you cant see faces close-up, only some portraits in the environment. and it is not always what you'd want to get....