Hi. My personal feeling is to see if a rescue centre has one. If you have a rescue dog there is a good chance the puppy training has already been done and often the rescue centre will have observed the dog to see how it behaves and interacts with adults, children and other animals. Then they know which is the best type of adoptee to settle the dog with. Also, small dogs often come up for adoption when their owners have passed away, so all they want is someone to love them and to feel secure again.
Personally, I hate the idea of breeding pups just so people can earn cash. If you buy a pup you have to find all of the above out on your own.
Good luck. And please post a photo when you find your perfect little companion x