I ordered the Rust Blast from the web address. Eddy Lucast must be your friend (I hope as your a great sales helper). We shall see how that treats the floor of the truck. I looked up the MSDS on this, looks like 2 active ingredients, Zinc phosphate and Phosphoric acid. I can not find a seller of the Zinc phosphate (in small quantities). It shows up in gopher and mole poison, so must be toxic and not sold over the counter.
Thanks for the suggestions. I did watch their videos, they are selling a system, including the final coat of paint, which looks pretty good for exposed frames and suspension parts.
I want to stop and fix the rust on the cab and fenders. But I don't want to go to far down that "rabbit hole" of removing every thing and exposing the frame. Mostly the frame is not in that bad of condition. I do want to fix all the leaks from old seals and bearings.