Dump truck purchase

We’re tossing around buying a dump truck. Looking for used but not junk. 18/20 yard and would be hauling rock or various sizes and dirt. Rock quarry is about 60 miles away and that would be about as far as we’ll would travel. We wouldn’t use that often so we couldn’t justify a new one. Would like to be 40/45k max. Which truck/engine combo should I be looking for. Thanks