Hi!
I am not sure if they are online but Bombay stores in Bradford sell a large range of fabrics in many colours and qualities.
There is also
http://www.myfabrichouse.co.uk/ - they are on facebook, not bought anything from them yet but again seem to have a lot of things.
Always worth emailing one of the companies as they may be able to get the fabric even if it's not on show.
Good luck!
Claire x