I know these posts are a bit old, but:
One, they are the same as the green A/C O-Rings. The green is a teflon
impregnation. Two- "Reputable" not AutoZone, like NAPA or a good well
sourced auto parts store will have them in Standard Ignition, Tomco, or
BGorg Warner. Car Quest supplies them branded as private label, but sare
Wells or Standard Ignition.