The rangefinder is the hard part. The price list at Jurgen Kreckel's site (http://www.certo6.com/purchase) has quick summaries of most of the reasonably common alternatives.

If you can live without coupling, accessory rangefinders can be had for cheap, and I've found them to be very helpful with the many scale-focus folders. But of course they are one more thing to do before firing the shutter.

-NT