Looking For a Couple Trucks that can handle off-road.

Hello, I know there will be many options and preferences along with opinions. I am looking into buying a few trucks to put to work. I currently have one 1994 international 9400, with a cummins N-14, spicer 9 speed. I use it to haul a belly dump. About 80% is not on paved road, I drive on a dirt/gravel mountain mine road. This truck is pretty decent it hauls the loads effortlessly works good. The down side is that almost every 12 hr shift something breaks off. l repaired: exhaust, ignition switch, rear diff bearings, mirrors..all small things. I haven't had any real big issues. I think the problem is that its a light truck, and parts aren't exactly too find. My question for those willing to help and give their opinion: witch truck would be a solid one that can withstand driving off road, and have parts that can be easily found. any suggestions are appreciated.