While I was searching for something for my wife I came across this site, eShakti. I thought you might like their styles since they stock up to 3X (53", 47", 56") and they will do a custom size. Many styles are 100% cotton or silk, although some are polyester. They carry tops, dresses and pants.
http://www.eshakti.com/customize.asp
http://www.eshakti.com/default.asp
http://www.eshakti.com/customize.asp
http://www.eshakti.com/default.asp
