I have both a Canon Canonet QL-19 and a Voigtländer Vito CLR. The first seems to me to have a better lens (besides being "faster").
The second one has a way better viewfinder - rangefinder, but is not as small as the Canonet. For a glass wearer the Vito CLR is probably better. A CLA is probably mandatory for whatever bought second hand, add $40 or so for the CLA to your cost estimation.

A more expensive alternative would be to look for a Minolta CLE or a Leica CL. Those are small, fairly inexpensive, mount Leica M lenses, have good overall quality. The Minolta CLE needs a battery (probably the Leica CL as well).

A Konica Hexar RF is another alternative I would take into account.

If you don't have a large collection of cameras which you use now and then, that is, if you use "only" one or two cameras, then batteries should not be a problem, just keep spare ones with you always, they are cheap after all and should never be a problem to have spare one with oneself.

A very good comparison of compact rangefinder cameras of the seventies can be found at:

http://www.cameraquest.com/com35s.htm