I'm looking at some billy goat model on craigslist currently. My question is what hp level should I be looking at? Some of my leaf clean-up are pretty big. Will a 12 hp model cut it or should I be looking at something like an 18hp? I've never owned a leaf/debris loader so any input is appreciated. It will somehow need to be compatable with my truck/ dump trailer combo. tailgate mount, sit in the bed or attached to the dump trailer while not paralyzing the dump feature.