Patrol 1985 or Navara 1997

Hi folks , I am looking at a Patrol 1985 Ute for transport of water in one of those 1000 litre tanks / shuttles.
Will be over fairly rough tracks on very large farm.
I can buy a nice Patrol 1985 diesel ute for about 6k , but a mate's father is selling a cheaper Navara 1997 diesel ute

I lean towards the old Patrol as it is easier to maintain and perhaps sturdier ????
But know next to nothing about the Navara.

your thoughts please :

A friend of mine had an early navara diesel non-turbo. It was very heavy on fuel and didn't go very fast.