If we decide to build a house we will be looking for a light truck home depot runner type truck. We would be looking for something around 700 to 800 pounds of payload (after all the seats are filled) and something that returns high mileage on the highway. I can see something like the 3.2 litre Ram being interesting. Being able to handle a 600 pound hitch weight (with the seats filled) and a towing capacity of 4000 to 5000 pounds would be a bonus. Anything above that would be a waste.
Re maintenance, we run four diesels out of 5 vehicles. The oil changes for the little smart diesels are pricey as they use synthetic. Around 55 bucks if just getting the oil and filter done. Fairly easy to do your self though as there is no drain plug. You use an extractor, stick the tube down the oil filler hole and suck it out. But it only gets changed once a year so I generally have Mercedes give it the once over which includes a bunch of other things including checking/changing the fuel filter which is another expense that the gassers don't have. Its easy to make it up in the amazing mileage they get if you do any amount of miles, not so much if you are only putting a few thousand miles per year on which is the case on one of our smarties. I can attest to one thing though, even small diesels pull very well. Smart diesels are only rated to pull 680 pounds but the motor is definitely not the weak link and the reason for low rating. (guessing the frame and the clutch). We tow with ours and other than slower starts as the clutch comes out it pulls the rated load strong on any hill. My point is a properly designed truck with a small diesel can probably do a nice job of towing lighter trailers like 3000 to 4000 pounds.