>Boy, you're shopping for the right camera! Each roll I put through mine (a Super_n) leaves me more awestruck at the capabilities of this camera design. Hard to reckon why it sells for such a discount to a Leica of the same vintage, given its build quality and design features.
My suggestion would be a super_n (also called the super_new), super_b, super_bc or S. These all have the recomputed tessar lens, and excellent layout of controls, etc. All will use the same accessories.
The super_n is identical to the super_b except for lacking the automatic setting. Mine was embarassingly cheap, and in mint condition, except that the film-advance knob had come loose and was falling off. This was easily repaired. The CLA was inexpensive, and it still cost 3 times what the camera did. My super_n has a working light meter (selenium cell, not through-the-lens) but I don't use it, I'm accustomed to metering off a gray card anyway and I do that with this camera just as I do with my other photo gear. I take the light meter readings "under advisement" and they are relatively consistent. The super_bc is a super_b with a CDS meter and TTL metering. I find that most super_bc cameras on the market have non-functioning CDS meters. A shame, as you could take advantage of metering through a filter if you had it. I am unclear as to whether the S models have any identifiable differences with the BC models, except for being the newest as they were made shortly before the 1971 demise of Zeiss Ikon. Again, look for a working meter.
The CLA will be a requirement, and well worth the price, unless you get a camera that has recently had one. It will free up the stiff lens focusing and the slower shutter speeds. The aperature setting (spring-tensioned pre-set mechanism) will be silky smooth afterwards.
Of course, the famous lens separation problem with the pro tessars limits the field; separation free ex&les are still a dime a dozen on ebay. The 115mm and the faster 35mm ones are the newest. Please take advantage of the proxars that go for $5 each on ebay, even if perfect. They work remarkably well. There are 4 different focal lengths.
Paul Butler