Fatfenders: Can you tell us first time "do it yourselfers" where we can get Zero Rust? Does it come in liquid (quarts, etc) and/or spray cans?

I am working on a 58 stepside and have rust in the normal places and some at seams. I have rust at the lap joint where the outside roof panel is spot welded to the shield frame? I can sand the exterior rust but will Zero Rust penetrate between the lap joint? Is there any other steps I should take before Zero Rust, like treating with a rust preventor? Do you prime over Zero Rust?

Silly questions but we got to start the learning process somewhere.