They sell racks like these at HomeDepot any where from 30" - 50" between the two posts. For the sheet goods you would want the 50" one. I think they are on the pricey side not to sure, You can also build your own, same idea, but out of 2x4 and you can customize them to your needs.
A Termite walked into a pub and asked,
"Where's the bar tender?
Apprentice atLedlie Construction Ltd "Never think you know every thing, when it comes to carpentry you're always learning"