Any good rust stopper/conveter suggestions?

[mn9driver]

1. I've never had much luck with rust converters.

They all seem to give you a paintable surface, but after a few months the rust breaks through again. The only permanent fix I’ve ever managed is to cut out the rust and patch it with metal or polyester/epoxy. If you don’t weld, epoxy is the next best thing, but it costs more than polyester.

Or you could replace the whole panel with one from a junkyard. They often even have one that matches your existing paint.