I need to borrow a knowledgeable husband to give me advice please!
------------------------------------------------------------------------------------------------
Hears 2 cents worth, 3/4 ton min, larger v8 ( I get better millage with my '16 6.0 than my '05 4.8 with or without a trailer ), stay away from unibody, lockers are great if you know how to drive with one. If your heavy on the throttle in turns you'll eat up rubber. same with sweeping turns on ice. One free wheeling tire (normal differential) will help anchor the rear in highway turns. That said a full locker (Detroit) would be the ticket. I wouldn't go with an ARB (they are the best selectable locker but with the air compressor & air line you'll have extra maintenance that you won't know about till you need it. I know, got one on the front of my toy, Detroit on the rear. The euro stile vans are nice but give me my Express2500. Extended is sweet (extra 22'' of space), But I've always leaned to standard wheel base just for getting around.
That said I've driven into the ground a '95 e150 (had a factory limited slip) and a '05 express2500 (bare bones) into the ground. My present '16 express had 22 miles on the odometer when purchased in March of '17.
If your going to wait till December to perches, try waiting till after the new year. I walked in with cash (they didn't want cash they wanted to finance) The window sticker said 35,000.oo, I offered them 25,000.oo. they laughed me out the door. 2 days later they called me up and said 26,000.oo. The next day a friend drove me the 55 miles to the dealer and I drove it home for 25,000.oo.
Never van dwelled but done a lot of sleeping (vaca, camp, stoned & drunk (don't drink no more)).
Now the hubbys can chime in and put you on the right track.