Several considerations here, John. First, need and utility are perhaps more important than one's budget. That is, there's much to be said for making a great deal of very little, for adapting and improvising, instead of having a special what have you for every conceivable requirement. If your J-8 is good, then an I-50 might have made sense: slower, but a lot smaller. The Summitar, for its part, is also collapsible and can do things which perhaps no other lens can manage. But its coating and glass are notoriously fragile, and your work will suffer if you don't use it with the right hood, the rectangular SOOPD. People make much of 1:1 finders. They are comfortable to work with, certainly, but I managed as well with other finders as I did with the nearly 1:1 finder of the M3 I had. It's generally best not to have an extra thingamajig sticking out. I have known people to swear by the VIDOM and the VIOOH, despite the small images they give specially with the longer focal lengths. Turret finders can be dicey. The Russian ones are of two types, depending on which way the optics lean above the foot, and if you get a Kiev/Contax type for your Leica you'll be in trouble. I was thrilled to win a 35-50-100 for my IIIc, but it was made for the Argus and getting it to seat properly is a problem I have only half solved. Why do you not consider the tele-wide Yashica or Helios finders? Much smaller, and the second costs relatively little. Those finders cannot compensate for parallax, but surely you can.
