BSI supposedly has W-177, among other interesting things like Augustiner, Ettal, and Weltenburg lager yeasts, to name just a few. BSI doesn't sell to homebrewers, though, but if you have a friend in the business you could ask them really nicely to order some...
I have been extremely happy with my results from WLP029, but it would be interesting to know how W-177 compares. Does anybody have a clue as to which of the breweries in Cologne might use the W-177 strain?
There is a very high possibility i can get this yeast from brewing science. My local brewery/buddy orders through them for all his yeast