Where can I purchase a 4 ft wide x 8 ft long x 5-7 inches deep ebb and flow plastic trays?

Where can I purchase Ebb and Flow Trays ( flood trays)that are at least 4ft wide x 8 ft long x 5-7 inches deep? Please help!? I need company names or web site links, product sites. I know they make them. I need help finding them!