Without getting a truck with a cage already installed prep time on it would be quite a few weekends so keep build time in mind when picking the first races to shoot for. Next is support vehicles with spare parts, including spare tires, and tools for race day repairs. This last part would be cool if it were a Ranger conversion trailer pulled behind one of the pit crew rangers.
I would add in my time but I think I would be more of a hindrance now that I move so slow but I can chip in a few bucks here and there and bonus parts I may have kicking around that is needed.
IFS 2WD would be best for Lemons racing due to its handling and lower center of gravity But the 4WD would be best of other style racing. My 2 cents for what it is worth is, For now, go 4WD and race that till a second truck, a 2WD, becomes feasible so at least for now all races are open to be entered. Simple off road to on road tire change with the normal suspension changes per course.