Hi Todd,
Looks like you have a great project ahead of you, from experience I know you have to spray a light coat of primer on the POR 15 while it is tacky or nothing will stick to it well. POR 15 has a primer they claim works on cured POR 15 but I've tried it and was not too impressed with adhesion.
I have a 71 Cuda I purchased 25 years ago, I had it media blasted and they said it looked really good.
Because I didn't want any rust returning I replaced both rear frame rails, both quarter panels, the tail panel, inner and outer wheelhouses, and the filler panel between the back window and trunk lid. I bought new front fenders from AMD, and a shaker hood also from AMD.
I built a rotisserie so I could flip the body over in my garage to work on it, also the people who did the media blasting had the car on the rotisserie so they could flip the body on it's side and upside down when blasting it.
Good luck with your project!