Try the English Shepherd Club--
http://www.englishshepherd.org/breeders-with-puppies.html
We have two English Shepherds, and I wouldn't trade them for the world. We got our female from Oklahoma and the male from Wyoming. They are great kid dogs, but they are great cattle/sheep dogs for us, too. I know the brother to our female is in Broken Bow, but not sure if they are producing puppies with him. I think Cedar Creek in Iowa has some puppies right now. I can look for the link for that, if you would like, or just search Cedar Creek Shepherds. Hope you find one for your kids---nothing like a puppy!