Thank you all for your answers so far.
Starting by the Voigtländer Kontur, yes, I took that option in consideration and I like the concept, what I don`t like is the fact I always need to focus on the camera range finder and then frame on the other. Lazy? Maybe I am, but...!
AS for the KMZ turrets, I have looked to many, they seem fine, parallax correction, optics for 28mm, 35mm, 50mm, 85mm and 135mm, not bad, but also not that good and the reason is simple, I wasn`t able to find one "right side"( for Contax/Kiev) construction, the ones I`ve seen are "left side" (Leica/Fed/Zorki) construction and I`m worried with the turret obstructing my rewind button. It would be ridiculous to take the turret off each time I rewind film.
The original ones from Zeiss are rightly built, but of course, they are very expensive.
Well, gonna keep looking but certainly I would prefer the Leitz 5cm, it`s small and well built, maybe one cross my path at a reasonable price.
As I´m planning to use a 50 alone with this kit, a smaller 5cm seems a perfect choice.
Once again, thank you all for your input.
Cheers
André