Looks like a lot of work, it will look great in the end I'm confident.
FWIW, I had a rocker panel fixed on my truck a couple of years ago. I'd crunched it on rocks being stupid without sliders. I found a shop willing to try because I was pretty explicit that my goal was superficially cosmetic but more rust and weather (the door didn't seal right anymore), so I wasn't looking for Concours d'Elegance here... I had a couple of creases but it wasn't quite as wrinkled as yours, primarily just dented and collapsed.
So they opted not to cut any metal out but tacked on a whole bunch of studs that threaded into a slide hammer, which they used to do the reshaping. In the end they wanted to put on a skim of Bondo, which I told them was not necessary since my truck is just painted with old school Toyota no-clear coat enamel that hides flaws fine. It actually looked really good, at least until my sliders flexed into my rockers and dimpled them.