I have a customer that wants his old 1800's rock wall exposed. Its behind about 15 feet of woods and the wall is about 300 feet. This is'nt regular woods, maybe its because its young? 15-20 years old? But its too thick to cut with a chain saw. Its way too thick to even walk through. Also way too much for handheld brush cutters. Only smaller trees throughout as big as 6 inches. Mostly bushes, vines, rainforest... stuff like that. So what do I use?