I have drake waterfowl waders and i wear wool socks and like the man said above, the diabetic socks as well..They are meant to make your feet warm and keep blood flowing, so for a duck hunter, thats gold.
Check out hunting socks as they are normally better made, anything 100% wool will help.
Dont skimp on warm weather clothes, especially since you said you stay pretty cold. Check out the cabelas line and drake waterfowl line. If i remember correctly, there was once a jacket that had built in "warmth" insulator, like some sort of double A, battery operated ssystem inside the jacket that put off heat.