[Biogon Bill]

JD, first of all there are no rangefinder cameras that have parallax corrected frame lines built into the viewfinder with focal lengths shorter than 28 mm. Given that your goal is street shooting, I assume that you want to strive to capture "decisive moments." This is a spontaneous type of picture taking that requires you to act quickly at times. Focusing in the camera's viewfinder & composing in a second accessory finder is too slow & awkward for me. It seems to me that you have 3 choices in a non-SLR camera.

The first is to use a 28 mm lens as your street shooting wide angle lens. It works very well for this purpose. Leica M 6 & M7, Zeiss Ikon, & Konica Hexar RF all have 28 mm frame lines built into their viewfinders. None of the Bessa series cameras have 28 mm in-camera frame lines.

Your second choice is to shoot with wider lenses is to take advantage of the great depth of field that these lenses offer - particularly when stopped down. Pre-focus or set the hyperfocal distance for a predetermined shooting range & then compose through the accessory finder.

Your third choice would be to use a 24 (Leica) or 25 (Zeiss) mm rangefinder coupled lens with a camera with 28 mm frame lines. The 25 mm angle of view, for example, is not that much greater than the 28 mm angle of view - 82 degrees vs 75 degrees, or 3.5 degrees on either side. There is enough extra room around the 28 mm frame lines to compose with either a 24 or 25 mm lens. This is true for any of the 3 cameras mentioned; in the case of a Leica M6 or M7, it is best done with the .58 magnification viewfinder. This approach will allow you to focus a rangefinder coupled lens & compose your picture in the same viewfinder. It will not be parallax corrected for the full 24/25 mm, but using the displayed frame lines as a guide, you can learn to estimate.

Good luck with your choice,
Bill