A lot of the military vehicle owners repaint using Behr Marquee Exterior Flat paint. I have seen the results and even 5 years later the paint looks great.
Harbor Freight cheap electric sprayer - $20-30
2 gallons of the paint (depending on size of truck) - $48 per gallon, but sometimes on sale for 40% off
Masking tape, paper and sanding materials - $30 for decent quality stuff
Take care of any major dents and rust, make sure you get a good scuff on the entire vehicle and then degrease and paint. After you spray, pull the truck in the garage and let it sit for a week or more so the paint can cure properly. The results will be pretty durable.
I am just waiting for the paint to go on sale, I have everything else and will be painting my truck with this paint once the weather warms up and dries out.