CDNN's website has a catalog you can download... and that's how you find out their deals. (That, or their mailing list, which you can get on.)
CDNN doesn't show guns on their website.
You have a local dealer or gunsmith order for you. Pay them for the transfer, and pay them for the gun.
I always have a copy of my gunsmith's FFL, and I can send it to whomever, along with payment. They ship to the gunsmith, and he handles the transfer.