Hi,
I'll second the comments about the Japanese "Helios" VF and add that they are still around brand new, if you search. Mine came with a neat little black case for the camera strap and frame-lines for 35, 85 and 135mm lenses.
Paying a lot more or getting lucky on ebay etc, the ex-USSR clone (by KMZ) or improved Contax 1930's universal finder takes a lot of beating. It covers 28, 25, 50, 85 and 135mm lenses with parallax adjustment for 1 metre and a central cross hair. But check for the right version as they come right handed and left handed. For a Leica etc you need the one with the barrel on the left of the shoe's foot.
Regards, David