Since the lenses on a MF camera will be longer, then of course the DOF will be shallower than 35mm. There are a number of 6x9 rangefinder cameras. The speediest lens I saw was f/3.5, though.
Originally Posted by jayvo86
For a really fast f/stop, the only choice is an expensive surplus aerial surveillance lens. Then you'll also need a shutter, and the lens itself might be larger than the camera.