The best known is probably Waxwear by Herbert Rice Fabrics. It's used by a lot of well known designers and bag manufacturers. The minimum is only 5 yards. Anything less than a full roll (about 50 yds) will incur a $20.00 cutting charge. Their website has been down for the past week for some reason. Below I listed the email address for sales inquiries. Feel free to shoot them an email and ask for a swatch book or any other questions. There's also British Millerain (link below). I really don't know too much about them, but their website is pretty informative.
nycwax@aol.com
www.waxwear.com
www.britishmillerain.com/