depends where you are taking it in the world but I would go diesel everytime. more economical, inherantly more relaible, safer to store fuel and fill from jerry cans.
I would only consider petrol if my main place of travel was to be eastern europe, then I'd get an LPG conversion
1990 Landcruiser H60. Full rebuild completed 2014
2012 Hilux, mountain top and bedrug with GG AT2s