snip...
-Best suspension articulation possible.
It would appear than many full-size trucks could work for you...as long as the cabs are large enough to be comfortable for your family. Though I agree with the others regarding a heavy-duty of some type, with your last point about articulation at the fore, I'd vote for a live-axle truck. However, there are so many other variables that go into chassis selection that 'articulation' may or may not end up being a deal-breaker/maker for you. A really big factor is if you are buying new or used, which I assume you already have an answer for...new choice is almost unlimited though expensive, used options can be more difficult.
Some specific examples I can share were part of my shopping for a new
gas-powered 1/2 ton [I'm not a fan of the arguably outdated 1/2, 3/4, 1-ton monikers, but they they are sometimes still descriptive], pickup in 2011. I had quickly and easily narrowed my search to the Toyota Tundra or Ford F-150 with a 3.5L EcoBoost engine, a relatively new power-plant at the time. Living and regularly traveling at 5,000'+, I'm a fan of forced induction engines, which for me have always been turbo-diesels.
In the F-150's favor was the EcoBoost, available OEM rear locker, gear ratios choices, and the extra control offered on their A/T [I'm a manual tranny fan, but couldn't get a manual in either truck.] Negatives included black interior and 20" wheels (on the Fx4 package), and fewer aftermarket, backcountry-focused choices for suspension and armor. The Tundra offered no OE locker, also had black interior with the (discontinued) Rock Warrior package I wanted, no forced induction, and probably less mpg and range.
After decades as a US-made full-size truck guy, I'd recently built a V8 4Runner, and loved the overall quality, feel, and aftermarket support for the Toyota platforms as compared to the Ford. The Rock Warrior package included less frills (I'm okay with cloth over leather seating), and forged aluminum OE 17" wheels with 33" tires. Though not a huge factor, in May 2011, there were some good rebates on the Tundra, so for what I wanted the Tundra was a few thousand less. The turning radius/wheel cut was also great on the Tundra, not sure how the F-150 compared there.
They were both "low riders" stock, like many base model 1/2 ton 4WDs. While the Tundra did offer more ground clearance if my memory is correct, both would need suspension mods, which is not always the case with taller, heavy-duty pickups. Both were IFS. I choose the Tundra, and in my most comprehensive buildup to date, corrected most if not all of its weakness, and have been largely happy with the platform.
The negatives for my use are that I've become a fan of slide-in popup campers—which if highly optioned weigh much more than many know or admit—and the short bed on the CrewMax body. The CrewMax cab is absolutely huge and comfortable, and though I prefer a longer bed I didn't/don't care for the "Double-Cab" Tundra cab styling. I've also since returned to my roots, with a manual tranny diesel pickup that I enjoy driving, a slightly longer bed, and better payload and range. (Better range stock-to-stock, but because that Tundra has a large, aftermarket tank, that is no longer an issue.)
I like the '14 Ram enough that it actually has helped me look at the Power Wagon platform that is being recomneded here, but they are pricey, and I'd rather drive the stick-shift Cummins most of the time,
for less money.
James