Fortuner would be my choice but the Everest is a good option too.
Great technical support country wide. Almost every dorpie has access to a Toyota dealer.
Great resale if you ever decide to move on.
Lots of aftermarket accessories.
Great support on 4x4 forums.
Amazing reliability when the vehicle is maintained correctly.
The Fortuner and Everest have rougher rides because they have body on frame chassis instead of the one piece monocoque setups that the other SUV's have.
Negatives are that the Everest or other cars look better both inside and outside.
I think the 3.2L Diesels perform slightly better than Toyota Diesels but I personally dont think they are as reliable as the Toyota Diesels.
Fortuner has dated infotainment setups.
400K is a great budget to get a great quality low mileage 2015 for less than that(+-R350K).
Or about the 2016/2017 version with higher mileage but they have really efficient and powerful 2.8L GD6 diesel.
If you want the very best reliability of all Fortuner and Everest models, I would look at the Fortuner 4L V6. The fuel economy is very heavy but the engine is near bullet proof and powers Land Cruisers and Prados to 100's of thousands of km's.
The diesel models are also very reliable and provide better fuel economy for a big vehicle but they have a lot more expensive parts that need to be maintained later down the line like injectors, turbos, diesel pumps, timing belts, etc. But this is 250k km into its life usually.
If you are just travelling run of the mill sand/dirt roads then you can look at most other brands SUV options.
But if there are deepish ruts and mud, I would probably stick with Fortuner or Everest.
If I was spending the money, I would get a diesel Fortuner 4x4 version. You might not ever need 4x4 if its just sand roads, but if the "overlanding" bug bites, then you will have everything you need to experience it as far as possible.