I like #4, at least for an attempt. The inner rockers are rusted out on mine and I plan on treating the inside of the outer rockers before I repair them. Tap out what you can making sure you have some type of dolly on the outside of the rocker as you hit on the inside part. For treating the rust, I like Corless over Por15, just my preference, but I've had really good luck with it. At some point the floor on my truck had the same inner cowl floor area repaired on both sides. Whoever did it, did a decent job.
