Maybe try Ducks Unlimited or Cabela's? I got some nice stickers of a Labrador's head for my truck from DU.
Contact Jo-Anne at Imagine It Custom Embroidery- she is a lab person and has BEAUTIFUL labrador stock images she embroiders and can make patches I'm sure. She made one for a chair I have. She also has a digitizer who can make an image for her to embroider directly from a picture of your own dog(s). Very cool!
Imagine It Embroidery
~Julie, Rogue, Monty, and Eddy~
"The reason a dog has so many friends is that he wags his tail instead of his tongue." -Anon
This might help!
Labrador Embroidered Patches