zak, if you have the MT version of the Fun Factor, there isn't much you can do to get more height, without performing some considerable modifications. PoorJudgement did it by using TMAXX wheels and driveshafts on his FF, this is the only proven method so far by anyone on this forum.
As far as the body goes. Pretty much any truck body designed for 1:10 scale will fit. They may need some minor alterations to things like body mounting holes and wheel arches but nothing too drastic. If you have a look at some of the picture threads, you may get some inspiration.