For not much more in the size dept a Leica CL or Minolta CLE would do manual control, and interchangeable lenses. but honestly I think I'd rather plunk down the 400 for a Contax T and just not worry about it. My M2 takes care of the rest.
Here is another vote for a Olympus 35RC. Auto exposure, you set the shutter speed, meter selects the aperture. Also full manual control with all shutter speeds and apertures available if battery dies or meter goes belly up.