I'm doing Purina One, I wouldn't fill bad if I was you. Honestly when it comes to the nit and griddy of buying dog food, it's a matter of what you think is okay for your dog. IMO its no different then getting into a argument/discussion on what humans should eat.
Yes, many farm supply stores around here carry the good brands. Also some foods have a food locater on their sites and will show exactly where you can get the food.