Good to know, I didn't know GM now has an OEM kit. Tells you they must get a lot of requests about replacing brake lines. I just looked at Classic and the stainless kit for your truck is $329, or $439 if you want stainless braided hoses too.
From what I know, the "coated" lines have some kind of external coating on them, not sure what though. Kind of like spraying lacquer on brass to keep it from tarnishing, the steel has some kind of finish on it that protects it from rust.
Minnow, you are correct, and hope they can get past this with the new management team, we will see. If I was buying tomorrow it would be a new Ram in my driveway.