55 chevy pickup door question

[wilberweb]

Hi, Guys
I'm starting on my door patch panels.I just got them back from the metal dipping place. My question is what should I coat the inside of the doors with to prevent them from rusting. I know about the standard epoxy primer,urethane primer,etching primer. I was thinking about bed liner, Or undercoating along with epoxy primmer.I wanted to get some thoughts on what direction to go.

Thanks for the help.

As always a great forum for this kind of question.

-Larry