I would say if its only used for gravel roads, really anything will do, if you are looking to get some clearance make sure to have a close look at the jeeps, although they may not be built as well as the imports they sure are good outdoors, I have driven Cherokee which did very well in snow and mud with no problems except gas milage, I have driven a RAV4 which has terrible clearance but sweet gas milage and very smooth ride, and I have driven a Jeep Liberty, it has tonnes of power average gas milage and can go anywhere off road,
My new truck is a Ford Explorer Sport trac, I had to settle for a midsize as it needed to fit in my garage, it seems to give me the best of both worlds SUV and truck, I love it and it does well off road too although I would have to pull off the running boards if I needed to hit a hard core trail