For Scudrunr, I have not bought any drums yet, but pricewise this is what I have found,
http://www.mcmaster.com/
and for 85 gallon (which I am leaning towards) try
http://secure2.data-comm.com/servlet...-Gallon/Detail
Sorry, don't know how to make hyperlinks for you.
From chatting with norcoredneck it seems the best way to go is a new unlined barrel and avoid any of the burning whatever was in the drum before.