Andy,
Loads of reading up to do in the stickies at the top of this site:-
http://www.hiluxsurf.co.uk/forums/forumdisplay.php?f=53
I know you don't have a surf, but some informative stuff in there.
My advice, if you go down the SVO route, check your fuel pump can cope with it first, and start slow, then increase percentages as time passes and no problems show. Change the fuel filter when you start using it, and then again after a couple of weeks - it lossens any crap in the tank and clogs the filter.