If I had to fill the bill as you state it, I would turn first (I live in the UK) to
www.jessops.com/classic
or
www.andrewscameras.co.uk
If, on the other hand, I wanted lenses for practical use, I would go for Voigtländer every time. I have a 50 mm and 28 mm with Leica mounts, they're good. The 50 mm f1.5 in particular is well ahead of a Leitz Summarit. Do you have any experience of vintage 35 mm lenses? Even if you can find some in really good usable condition, performance can be very disappointing by modern standards.
I had a Kiev (4a?) once, didn't think much of the 50 mm lens, although I have a 135 mm Jupiter lens (Leica thread) which is good. If you decide to go for vintage, I would test the lenses and look hard at the results before you spend a lot of money!

Regards,

David