I have a 2Lt in my LWB prado 91, gives me 6.5-8.5 per lit depending upon the shifting and of course, how you paddle the accelerator. That makes 5vz a strong candidate if considered a swap. The fuel consumption is reasonable given the power of the engine(it's a 6 cylinder engine whereas 1kz is 4). It's Petrol.
You can also consider 1jz 3.0 lit supra engine. It is cheaper than the kz and vz engines, and gives reasonable power the rig. Can't comment on the alteration techniques though. I'm sure it's nothing a qabil mistry can't handle.