I picked up a 97 cummins auto xcab 4x4 dually a couple years ago. It had 220k miles and was a good truck other than the interior was very dirty and it was aggrevaiting for the kids to get in and out of the back seats. It was a work truck for the previous owner and it showed but it was a good running truck.
I currently have an 01 Ford Crew cab 7.3L 6speed 140k miles. Plenty of power and more room for the kids. Nicer truck but I had to pay more to get that.