I'm sure Denny will chime in when he sees this, but in case you are in a rush . . . my notes on Brewtek CL-50, which is what Denny's Favorite is, say to ferment between 60-70F, so 15.5-21.1 F. It looks like the website is the best source of information in this case.
As far as I know they have dealers in various countries, but there is no European affiliate of Wyeast. If there is I'd love to hear about it.