Gatorback is working on getting them created. Sign up to be notified when they are ready here, https://docs.google.com/forms/d/1p94khx8afU-LAyrf7nnUmdLjXuqKNHSg-75pe0KAK-4/viewform
No, they only work on the Silverado. Gatorback is working on the caps for the Sierra HD trucks. You can sign up here to be notified when they are ready, https://docs.google.com/forms/d/1Zmq-jNvCc00dTpAnCm4VlBu9GcFRrFZY1dWmJz9zT58/
Gatorback only has the 4 piece set for the Silverado HD. There is nothing in development for in the front of the rear wheels for this generation of the truck.