One of my favorite fabric sellers - has tons of tone-on-tone fabrics:
http://stores.ebay.com/QUILT-UNIQUE-FABRICS-AND-GIFTS Great prices, no inflated shipping costs and always very fast service.
I've bought a lot at fabric.com - sign up for their newsletters and get discounts by email.
Another really good seller is www.whittlesfabrics.com - huge selection, discounts and very fast service.