I think you would spend more time and money fixing it than you would pay for a donor.
Another option to consider while you are looking for a donor, would be convert to a flat bed.
I'm not a professional body person, but I've done a pickup bed broadside similar to yours and it ain't pretty. A lot of time and effort.
EDIT, just saw your other post and you already have the bed off. So you halfway there to a flatbed...