I've got some surface rust, before the rear fenders end up with holes I wanted to take care of it, I've sanded it down to bare metal and looks pretty good, what would be recommended POR 15, Chasis Saver, or something else? Those are the two I've heard of and looked into. Probably can't stop the rust entirely but if I just slow it I'd be happy, I plan to cover it with fender flares after I put something on there anyways.

 

I used some Chassis Saver on my frame. But underneath the bed, inside the fenders and on the outside of the body, I am using a two part epoxy primer. I have some pictures and write-ups here;
https://www.ford-trucks.com/forums/1...l#post11408747
I also belong to a paint forum. They are very professional, and have very good information. Here is the link;
SPI User Forums
And here is the link to their website;
Home
I do not plan on making my truck show quality, but I do want it to last another 30 years or so. Whatever you chose to use, I would say if you do your research and do a quality job, it should last a long time. Good luck with your project.