try http://www.plastic-mart.com/class.php?item=137 . I have just ordered the 15 gallon fully draining conical after many emails back and forth to make sure it would work. this is F.D.A. approved linear polyethylene. the have many sizes and the prices can't be beat. My 15 gallon will fit in my freezer adapted fermentation cabinet.
just a bit of a note. I got a 55 gallon plastic drum that I paid $35 for. I got it from my HBS. It is what his malt came in. He sold them whenever he emptied them. That would be where I would check before I spent the money on shipping.