I know that they carry the loc-line connectors and valves at The fish store and more in Buckhead. I've seen a few boxes full when Porter was making a feeding station for me a few months ago. I've never seen them at Marine Fish, but I wouldnt be surprised if they are hidden somewhere, since that store has everything, lol!
Aquabuys carries them. I'm not sure if he has them in stock right now but he should be getting some more in I'm using the 1/2 and I got the last of his stuff. But give Sam a call I think he has some in.