Over the Rainbow and Marshall Dry Goods have a variety. I have ordered from both, but not the backing (yet, but will be as soon as I finish my tops). Marshall Dry Goods has a variety of widths from 90"-118" I think.
Over the Rainbow:
http://www.overrainbow.com/cgi-bin/S...enu-70000.html
Marshall Dry Goods:
http://<br />
<br />
http://www.ma...duct_list&c=66
(edited to correct size to 118" - sorry, not wearing my glasses) :)