There are two trucks that are universally liked for dune bashing – Jeep Wranglers, and Toyota FJs and Fortuner (basically the same truck with a slightly different body style).
I have owned two FJs – rolled one in Sweihan doing an advanced drive right after a rain storm. The FJ saved me from any damage, but it was rolled 4 times down a bowl, and written off.
They are built TOUGH. Many trucks wouldn’t have survived that – we drove it out of the desert after we replaced a tire, and re-inflated another. AXA still wrote it off, it had significant body damage – but I was OK, just spitting sand.
There are few trucks with as much aftermarket support, that are reliable. Maybe the Pajero, but it has a smaller, less powerful engine… The Jeep isn’t as reliable (but I do lust after its visibility!).
Yes, you should buy an FJ. (If you had the money for a new Bronco, I would say that is an option, but they need a year at least to prove themselves… )
Be sure to get it checked out by a competent mechanic if buying used. Make sure they test the engine compression as part of that. (I recommend Rajesh Paul Paul of Marshall Automotive… if you need a recommendation.)