You can’t go wrong with these guys. 2nd South Carolin String Band. Live at 145th anniverary of Gettysburg.
http://www.youtube.com/watch?v=0sB0McDpAjM
I have a couple of recordings by the 12th Louisiana String Band & Benevolent Society. I couldn't find them on YouTube, so I looked them up on Google and found the Southern Heritage Music Awards which gives the names of a number of other groups I'd never heard of that sing of the war and the South. Here's a link to the SHMA site: Link