I don't think I'd worry much about the electrical draw unless you are opening and closing an awful lot or don't have a decent alternator. It would certainly use less battery juice than an electric winch on a Jeep. On average, while using my grapple to clear brush, I am opening a closing the grapple about once every few minutes at most and usually less often if you count the time traveling back and forth to the brush pile etc. I'd imagine you could get away with a relatively small motor so long as you were satisfied with just closing the grapple rather than crushing with it. That would certainly help the battery life too.
Having said this, if you have a set of rear remotes that is by far the quickest, cheapest and easiest way to set up a grapple control.
