Greg and JP hit the nail on the head,not a place to cheap out. I would wait and save the money for a Mohawk or Rotary.
This is my choice, a bit spendy but Im filling the penny jar, check out the Mohawk tire engaging option, now you have a 2 post and 4 post combined,
Http://www.mohawklifts.com/wp/consum...ging-adaptors/
Rich