In my poking around, I found that 4 wheelers are constantly looking for power assist for their steering. Apparently the really wide mud tires they use are hard to steer when they are rock climbing and the tire gets into a tight spot between rocks. Rather than replace their entire steering system, they use aftermarket ram assist systems to do the job. I found one system (sans pump and pulley) for $245. So for about $500 or so I might be able to rig something up.
