If you truly have your sights set on a Lance 855s, then you'll be fine with a SRW one-ton short-bed truck. You said that you want to do some "heavy boondocking." If that's the case then a dually will limit you on where you can go. I just bought a Ram 3500 4x4 SRW short-bed truck with a 6.7L Cummins diesel and it has a payload of 4,300 lbs and a GVWR 11,700 lbs. Plenty of payload for our 3,000 lb Wolf Creek 850 and then some. As was mentioned, diesels are heavy. Getting a gas engine instead will give you an additional 700 lbs of payload.