I would not buy a used Bill Goat. When the metal bent, it pushed the battery into the muffler almost causing a fire and the battery to short out. I will definitely get you some pictures to look at, but I would look into the Giant Vac Value Line Tow Behind. While I was dealing with warranty issues on my Billy Goat, I found this machine.
http://www.giant-vac.com/industrial_tow_behind.php