First thing to consider is that anywhere past the US, Canada & Mexico very few have even heard of Chevy, Dodge or Ford. What are you going to do when something goes wrong? It will.
Better find something that is more of a world truck than what is only known in North America.
There is a reason for the VW Westfalia being so popular with true world travellers. There are many vans which make great class Bs sold by Asian builders sold around the world but are totally unheard of in N America.
I would expand my research beyond the world of .com N America & see what is out there in .au , .gb & . wherever else RVs are built & used to find a common truck base that is built upon.
Truck size is not an issue. Large trucks are everywhere. Servicing & parts availability are key.