Thinking the easiest way to do this is to find something in white twill and then dye it, I started poking around. The Dickies coveralls don't come in white, so I ranged farther and found this.
My take would be to get two, one long-and one short-sleeved, zipper front, no pockets. Remove the long sleeves from that one and sew them into the armholes of the short-sleeved one, then use the rest of the extra coverall for pocket and neckseal material.
Being a poly/cotton blend, I'll probably have to use more powerful dyes than RIT, but I'll have plenty of leftover fabric to experiment with.