If your going to use this truck for double duty a standard dump truck plus a chip truck make the top half removable so the truck can be machine loaded when hauling gravel. The second thing I would get a 11-12 foot box a 8 foot box is too short I personally wouldn't have a truck with a 8' box.
The sides on the truck shouldn't be any higher than 4 feet tall from box floor to the top too tall the load gets too high and you can roll the truck over dumping the load
It would be expensive but aluminum upper structure would be the way togo even light steel is heavy you could add 1000lbs to the truck using steel. You can use plywood but that doesn't last that long and it can be heavy also and its a maintanance item keeping things painted.
Hoist selection on the truck the best is a telescoping post hoist it lifts the most and gives you the best dump angle and gives the box more stability when dumping. The steeper the dump angle the better you don't want tobe prodding at a stuck load with a pitchfork with the box up and all of a sudden it lets go and buries ya.
Truck selection what type of 1 ton are you looking for if you only need a 2wd go for a F-Superduty or a 3500HD Chevy both 1.5 ton trucks. I own F-Superduty trucks and theres no comparision they can out work a standard 1 ton anyday I have had 9000lbs of gravel on my truck with no problems.
I know of a chip box all set up with a subframe hoist and power pack it come off of a F-350 Ford 4x4 its forsale but one catch its in B.C. Canada.
