Have a look at the pages at www.photoethnography.com She has a great compilation of information about a lot of small rangefinders.

I personally carry a Petri 7S, which is fully manual with coupled RF. The meter is on the top of the camera, which is a little wierd, but it works.

I've been looking for a Yashica GX, but they seem hard to find at a decent price.

Best,

Will