Dear fellow
Rather than considering prado with 2LTE, you should consider Landcruiser II (usually govt or NGOs auctioned), it comes with 3L, 2800cc, non-tubro diesel engine, it will meet your requirments well with good fuel economy and easier maintenence too,
But one thing you should keep in your mind that these old school Prado/LC are not designed for high speeds, means that you should not expect 150km/h on motorway on a hot sunny day with 7 adults and luggage onboard with this 3L engine, if this is your requirement than only 1KZ may be able to fulfill your requirement.
Reason these old school vehicles have poor aerodynamics and in that era highway speeds even not exceeded beyond 100km/h. And as you go beyond 100km/h your main limiting factor is air resistance.
As per my little experience I just sold my 1989 HJ60 with stock unovehauled 425000 kms driven, 2H 3980cc, inline six cylinder non-turbo diesel engine. I once got 11km/l in Feb 2014 on GT road from Lahore to Multan without AC and consistent speed of 90km/h only two adults onboard.
Whereas I got 8.5km/l in July 2014 without AC but I kept my speed around 100-110 km/h early morning drive on same route with two adults onboard.
And going for an old school SUV you should keep yourself away from hassle of electircal sensors as much as possible try to get a manual vehicle if possible.
Here is a thread of my mega trip to north, enjoy:
https://www.pakwheels.com/forums/4x4-clubs-off-roaders-suv/223440-4x4engaged-winter-september-2013-a