Pet store dogs come from puppy mills, go read my posting about them in the General section.
Why do you feel this breed is good for you? How did you research this? Like the others say they do have a lot of health problems.
Maybe if you tell us all about your lifestyle and how you live, house / apt / yard / fenced in or not etc... if the dog will be alone for extended times. Perhaps we can give you suggestions on breeds or types.
There are a lot of wonderful rescue organizations. I would much rather you support them then the puppy mills! Continuing to buy from pet stores supports them and their evil ways.
This is what their living conditions are like before they arrive at the pet store. Did you get your money back?
Notice the dead pup in the tire.