For a listing of breeders that does the appropriate genetic testing.......http://www.boxerworld.com/breeders.
Hopefully, one listed is in your area.
There are many breeders that do (and do not) do genetic testing. Genetic testing is VITAL for the health of our breed. If you find a breeder, please be sure to screen them and ask the appropriate questions. If they can not supply the hard-copy documentation of the genetic testing, please do not purchase from them. Any reputable breeder will be glad to furnish the documentation.
Never go to a petstore to purchase a puppy.
Another avenue to help aid you in your search........contact your local boxer club, contact your local boxer rescue, or go to a dog show in your area for a referral to a reputable/responsible breeder. All need to be screened. Remember, ASK QUESTIONS!! You will not make a reputable/responsible breeder mad by screening them, as they will also be screening you.
Good luck in your search.