Hello and welcome! You have asked the question where you will get a pretty well 50/50 split in answers. Both have merit, and both have disadvantages... In my opinion I think the first thing you need to do is work out how much space you want and how much gear you plan to carry, as this may well dictate the truck you buy. The Mog owners will always vote Mog, as they have one... The NG/SK owners will always vote truck, as they have one!! I have the latter and will give you the reasons why we chose a truck over a Mog. Note, I have nothing against Mog's and loved driving the Ag Mogs in the UK.
So, why do we have a truck... We plan to live in our truck for a few years, so chose space over off road ability. Our Hab Box is 6m long, 2.5m wide and 2.2m tall. We have decent room to be comfortable inside when the weather outside is bad. We plan to do a lot of remote travel, but not go rock crawling so think the truck will be more than capable for our needs. If we meet a track or obstacle where I have to question driving it, we won't. The truck comes with heavy over engineered axles and transfer box, along with a huge unstressed V6 engine, so will sit at 90-100kmh all day long without getting hot and without breaking. The chassis will happily cope with 11 or 12 tonnes all day long. The truck option has the cab over the engine, and with our 4.3m wheelbase, our 6m hab box sits nicely on it. As the wheelbase is 4.3m we have lots of chassis space for a big semi fuel tank, 1 of two water tanks, start batteries, gas locker, AC base unit, recovery gear and spare fuel locker, tool locker, hidden locker under spare wheel carrier, chassis mounted drop down twin wheel carrier. This means the body is kept free of a lot of stuff. I see all this as advantages.
However... There are disadvantages... Because it's a 'truck', it is easy to get carried away with your build. I now have a 7.8m long 3.5m high and I'm guessing 11 tonne home on wheels. It's big! This is where having a Mog wins. You can't go crazy big on a Mog, so have to really plan what yo carry. Ian and Trish are a good example of this (Unimog Adventures on Youtube). They have crammed a lot into their Mog but still have a reasonably nimble machine. They have just uploaded a new video on their thread on here which is worth a watch. Read all the threads you can, work out what you 'need' and what you'd 'like', and then plan from there. Most importantly, take your time, allow for even more time, and be advised that building your own truck will consume you both!!!