Triggerguard's that wide huh?
Did the Power Speed holster have all the spacers installed? If so, I bet you could modify it to fit by adding some washers between the spacers and useing longer screws.
How about a Bianchi Limited Hemisphere?
I've got a Gilmore holster I don't use anymore. I'll take it up to the range Friday. I think they have a Walther in the rental case. If the holster fits, I'll give you a good deal on it.