Research Cabela's.

I have this cart. It does fold but I sure would not want to pack it in. To lighten it I'd get rid of the solid rubber tires and go to aired bicycles tires. That would save you some wt.

They are not as easy to pull or drag as you think. The cart will have a tendency to tip over. The picture I am providing I use to haul turkey gear in through plowed farm fields. In heavy rough terrain it would be useless.
The other reason I got this cart was for a shoulder injury to which the Dr told me not to carry any wt on my shoulder. So I dragged it with my good arm.