Another thing to look for is a fatigue mat. They use them at factories to stand on in front of equipement. You can find them at hardware stores, I think Sears has some also. They usually come in 2x2 mat or larger.
Try an auto parts store, like Autozone or Kragens. They have mats that are black faom. the down side is they come in packs of 4pcs.- 2.5x 2.5 feet. You'll have enough to make everyone you know at least 2. lol Good news is they are less then $200.