There are plenty of aftermarket suspension systems for the Ranger, both TTB and A-Arm. A lot of the dezert guys go with the lighter Ranger, because the suspension doesn't get beat as "much" as it would on a fullsize...relatively speaking.
That picture is actually a full size Bronco that I'm pretty sure was built by Mark at Southwest Performance. But, Autofab does build a kit to bolt-on a full size F150/Bronco D44 TTB like the one above on a Ranger/Explorer/Bronco II. And yeah, it can work incredibly well in the rough. I think the TTB would be well suited for Overland travel. It'll never perform like a solid axle, but it'll get you into almost as much trouble!
The TTB's weak point is the center/crossover u-joint. But, if set up right (appropriately placed bump stops and limit straps), it can hold up very well. For high-speed use, the center joint is a non-issue as desert racers do not generally run in 4wd.
The 2wd A-arm Rangers aren't great foundations for hard-use without a lot of modifications. There are a few good kits for the 4wd trucks, though. If I was building a 4wd A-Arm Ranger I'd look at Dixon Bro's first... not high on bling, but high on function. I'm a beam guy myself, though, so I'd go with a TTB truck.
Engines: The 2.3L and the later 2.5L are both great engines. The 2.3L is one of the most reliable engines ever. Especially after the converted to the roller cam. Still, by the time you add some lift and big tires, they really start to run out of power. Keep things modest with 31" tires and it'll be fine.
My choice would be the OHV 4.0L. It makes really great low end torque, plenty of power to motivate the truck even with larger tires (as long as it's geared). Best of all, it'll net at least 20mpg on the freeway. Even after several hundred thousand miles. I've owned at least 4 trucks with this engine and each of them had at least 230,000 miles and still ran great when I sold them.
The later OHV engines make great power but their fuel economy sucks no matter what you do. I don't think the extra power is worth the loss of economy. A full size truck can get just as much fuel economy and also give you more payload, towing capacity and overall room.
On a related note, I think an Explorer would also make a decent Overland rig. It uses all the same suspension components but has 4 doors, plenty of interior space, fold down seats, etc., etc. I'll be building another 4WD 4 Door TTB Explorer once I get tired of my current Bronco.
My old Autofab equipped Explorer (same suspension as a Ranger):