Anybody know where I can pick up a few cans of the "Satin" Black for the engine compartment locally? Can I pick some up at a GM parts counter?

Has anybody ever tried Rustoleum's products such as the Rust Performer that turns rust into a primer or a paintable surface without having to sand to bare metal? Or the Rusty Metal Primer or Clean Metal Primer?

I'm going to be doing some prep work in the engine compartment before I drop in the newly rebuilt 455 with all it's shiny parts. I just don't want to drop in such a nice engine in a crummy looking engine compartment. I'll plan to later down the line bead blast the entire car and compartment and start from scratch but at this point, I would like to get the engine in soon so I can park it in the garage for the full winter season.