1) That motor is a total dog. Many compact cars today have more power.
2) 150,000 miles might be approaching the end of its life. Yes, it may last longer in a pickup, but in a high-profile rig this seems to be the upper limit. That's why so many buses and delivery trucks are off-loaded at that milage, vs other diesels which usually are kept to 300,000 miles.
3) If you know nothing about diesels, do your research before even considering one. Diesels can require more maintenance, and if you can't or won't wrench yourself, it can become much more expensive than maintaining gas motor, since shops charge higher rates and many common services require more labor time.
2000 Ford E450 V10 VAN! 450,000+ miles
2014 ORV really big trailer
2015 Ford Focus ST