I've found using a good sweeper works well. Parker comes to mind, some Brinleys are fine too.If you look at the brush set ups- the best have 4 brushes per side, the worse 2 brushes per side.

I have a Billy Goat Small Frame Force (F601S). The directional control for the shoot makes it great for hills. Another big plus for this unit is that it weighs under 80 pounds. A bit pricey though, around $700 new. If you look around you may be able to get a deal on a used one or on a used 5HP Little Wonder. Stay away from old ones (10 years+), they are heavy and loud.