agree that the Surf under consideration isnt worth your time and energy, hunt for better options.
20+ years diesel SUV will not be reliable (until maintained by yourself from a SUV specialist), will not be fuel efficient (dont expect anything above 8km/l), robust maybe if reliability is achieved. Petrol 2.7 (not 3.4) serves your purpose well and would be easier to maintain, run and closer to a sedan feel. If possible, test drive all 3 versions, 3.0 diesel, 2.7 and 3.4 and then decide.
Great idea to get the vehicle checked by a specialist, you can discuss the maintenance, running costs, ownership experience of Petrol vs Diesel with them.
Dont forget to test drive a 2.5 million Corolla as it might be the best option for your use