Have you gone to the dog shows and approched breeders/show people of the yorkies you like in the ring? That is a great place to start. Approach them after they are finished in the ring though. Once they see you at shows - they will know you are serious, so don't be surprised if you are turned down at first. Also join a local dog club in your area. That is also a great way for people to know you. You can also check out the show wins through the AKC event link of previous shows online. P.S. It will be a little easier purchasing a show quality male than female. It didn't state which sex you wanted, so I guess it didn't matter.
Best of luck!
T.