Lee
Try
Rangefinder Forum. Both lenses are highly thought of, as also is the Zeiss 21 f4.5.
I use a 25 and 35 Biogon on a film RF and both are great lenses, with very consistent colour etc.
There are a lot of M8 and M8.2 users over on RFF who should be able to comment onhow they work with an M8/M8.2
Mike