[BostonRott]

If you want to get involved with obedience, or other dog sports (or is that work??), you will be better off with a dog with some drive.

Just because a dog has drive does not mean it's an unlivable mess. Drive means a dog gets easily excited about it's work, has a high interest in either food, toys/tugs or hopefully both, and that this excitement in toys/food is easily channeled into the dog's work. You can temper the "mouthiness" of the dog just as you would any puppy. However, it's nice to have tug as a game for rewards, it can really help you with particular exercises later in life.

Ideally, you would want to look for a breeder who is out training and trialing their own dogs. You want to look for dogs who come from a working background, as this shows generations of willing workers. A breeder who is training and trialing their own dogs will be more familiar with temperament traits, and what is better for a working prospect puppy. Also, such a breeder will probably put strong emphasis on good structure and health.

Good luck in your search!