If you have a Craigslist or an Ebay Classifieds in your area; you can post a thread that you are "Looking" to buy a Chihuahua. Just make sure to specify that you're looking for reputable breeders; who do health testing... that will weed out any of the BYB'ers or puppy millers looking to make a quick buck.
All 3 of my breeders list on nextdaypets.com and my girls are all AKC registered. One breeder stands far above the others but have a look there. You can search by breed and then scroll down and filter by state. That is how I found my last 2.