One bet is to go to your local HD or Costco etc, and ask if they have any scrap usable racking for sale. Alot of stores keep a bunch of pcs lying around.
Racking MFG
http://www.naseco.ca/pages/page_46.asp
or look for distributors,
http://www.arpac.ca/about_arpac/aa_facilities.shtml
That racking is not cheap, beware.