Brando

Alright, so I just cut out some sections of my rocker panels on my 2000 cherokee. Couple things I want to do before I weld in the patch panels. I want to clean up the surface rust on the inside of the rockers... I plan on using a drill with a 3 foot bit extension and wire wheel to achieve that. But then I want to put some kind of coating/rust inhibitor. I was thinking about maybe getting some rustproof from the dealership and spraying the insides full with that but is there something better? Also, there's a couple places where the pinch welds are letting water in should I just fill it with kitty hair or is there a better product? Same thing goes with the bottom of the doors, I grinded out the sealer, what do you guys suggest I replace it with?

Thanks.