I agree with Stephanie! I have been with a rescue for 15 years, and we have had "Puggles", "Labradoodles", and all of the "designer" dogs, long before they were purposefully bred. We have definately had dogs that I would swear were Shih Tzu/Toy Poodle/Bichon mixes. The difference is the ones in rescue are generally $65.00 - $200.00 and include shots, spay/neuter, heartworm preventative, etc, etc, rather than an "as is" pup for $1000.
You might save some money, some time, and a life (as we get most of our pups off of death row in animal shelters), if you want to check Petfinder. A designer breed example - the night before last, I placed my foster puppy - a Rat Terrier/Fox Terrier mix 12 week old puppy (her parents were registered), in her new home. She and her brother were both dumped in an animal shelter before coming to my house.
Good for you for not wanting to fly the pup, though! That way if you do go to a breeder you can look around, too, and make sure it's not a puppy mill!
Also, and I'm sorry, I know I'm giving unsolicited advice, but I'm hoping it helps you, but with babies/toddlers at home, I would recommend an adult dog that is good with kids, or a larger breed puppy rather than a small breed puppy. Sometimes that lack of coordination that our human babies have accidentally teaches dogs to start hating kids. If you do get a puppy, watch carefully to make sure it isn't carried around by the kids, etc, so it doesn't start nipping. That ends up in making everyone sad!