So I called the store, politely asking what they might be if they aren't Silkies.
I got a manager, and she was rather upset with her employees for telling me they were Silkies, because they don't know what they are. She said they come in a box that says assorted bantams and that's all they know about them. They don't even have a list of possibilities. I'm hoping for the Cochin, I think they're prettier than Brahmas.
Thanks for the help, guys!