Are my rear fenders too rusty for repair?

[STPL]

The rear fenders are looking pretty worse for wear on this truck. I'm assuming theres more rust under the paint and I have a feeling I'm going to be losing most, if not all of the fender bulge. Being from the north east I know I can never stop the rust completely, but I would at least like to slow the process. Can I get away with wire wheeling/sanding out the rust, primer and painting and then making up the lost area with some plastic fender covers? Any advice on tackling this job?

http://imgur.com/gallery/J7va7

 

[1996xlt]

If you're good working sheet-metal it shouldn't be too terrible to cut out and replace with the patch panels sold by LMC truck (lower left diagram, part "1"): http://www.lmctruck.com/icatalog/FR/full.aspx?page=21

If metal work isn't your thing, remove the bed and replace it with something less rusty from the junkyard.