Best bet for a "barrel" for making a cider/brewing/whatever in, is a 5 gallon glass jug, called a "Carboy".

You can find them cheap sometimes in random places, but brewing store will have them.

The reason for this over a barrel is Sanitation. There are a lot more yeasts/infectious agents floating around these days, as opposed to back in the day (increased industrialization will do that to a society) so you really want to make sure you're doing a clean environment, and only exposing the sugary source to the right kinds of agents.

badger