so I've hit the floor pan, inside and outside with the rustolium rust reformer.

so do I paint another coat over that? and iff so? what? just an enamel?

From Rust-Oleum__ Not sure if the stuff works or not?

ABOUT RUST REFORMER
Stop rust in its tracks with Rust-Oleum® Automotive Rust Reformer. Without sanding, the coating bonds with rusty metal transforming it into a flat-black, non-rusting surface.
Instantly convert rust into a protected, paintable surface
Prevent future rust and corrosion
Odorless, water soluble and safe to apply
Compatible with oil-based, lacquers or aerosol top coat paints

FOR BEST RESULTS
Apply several light coats a few minutes apart to prevent running and sagging.

AVAILABLE SIZES

I use Ospho. Great rust converter. But I would NEVER use that as a finish. Definitely paint over it to give you a better chance of keeping it from coming back. Seal it! Rust needs oxygen. Better to suffocate it than risk feeding it.