I am shocked, upset, and a bunch of other emotions....nothing near to what I'm sure you're feeling. My flock is small, and new, but I had been warned by more experienced breeders to never bring a client to your home. I'll take that advice seriously now.
I'm sure you've already contacted the APA, ABA, ASBC, and Poultry Press, the local Poultry clubs; hung notices in all the local Feed stores. You've already installed security cameras, but I don't think the thieves will be back. I also don't think the thieves will be showing or selling the birds. From what you've described about your interaction with the oriental man---you may have your thief pegged.
I am so sorry for your loss. I seriously doubt your wonderful Silkies would end up in western NC, but I'll keep my eyes and ears open.