Here are some rescue places that I've found that appear to be reputable rescues. Even if there are no pups available online, I'd email or call them and see if they have gotten any in, or know of any that are coming in, and they haven't gotten a chance to post it on the website yet:

http://www.gsror.com/
http://www.adoptapet.com/pet/8579981-denver-colorado-german-shepherd-dog
http://www.malinoisrescue.org/
http://www.coloradorhodesianridgebackrescue.org/happy_tails/
http://www.coloradorhodesianridgebackrescue.org/