Check out these folks...24 1/2 years travelling the world in an FJ60.
http://www.weltrekordreise.ch/a_starte.html
Also you should check out the magazine "overland journal". It has great articles about expedition travel.
I don't understand the need for "more power" especially on an expedition/excursion. Isn't the point to experience the journey? Reliability and simplicity need to be the key factors.