I have an extra 55G drum I bought brand new a few months ago. It has 3/4" bulkheads top and bottom welded in by the shop that sold it to me.
I was going to run 2 barrels but I think just 1 now.
Check out my mixing station thread here for pics of its twin:
http://www.canreef.com/vbulletin/showpost.php?p=728214
Brand new they are $100 but guaranteed not to leach any previous contents. I went this way because a few of the used $40 versions I saw were stained with who knows what and I didn't want to risk it.