Can anyone recommend a good Animal Behaviorist/Trainer on the West side (Westchase/Sharpstown/Memorial area)?

I have a lovely dog who is very anxious around strangers. He understands the "rhythm" of our house and generally does what we want but does not follow commands. We took him to a couple different obedience training classes at one of the big pet stores and they said he was too anxious and we needed to hire someone to come to our house. Can anyone recommend a person or a company that might be able to help?