Rent a dozer an do it yourself .
He said 1/2 acre wooded "lot" so I'm assuming he's in the city or a subdivision somewhere. You're not going to burn and your not going to be able to do much with just a dozer in those applications. Excavator is the way to go if you're clearing lots around other stuff. Take it all down, cut it up and load it into dumps for haul off and backhaul your fill on the way back to the site. Then you bring in the dozer and and a root rake.
