Bernatex makes a fabric they call 'Atmosphere.' It comes in a brown that would be very pretty as a border for this. It's got swirls of different browns in it.
http://www.benartex.com/?page=galler...g_c=1&idp=7473
I used it for the border of the Jesus quilt posted on this thread:
http://www.quiltingboard.com/t-75293-1.htm