I use fabric. com alot. I have tried connecting threads. Both have pretty reasonable prices and quick delivery.
I have come across a place called
http://aaaquilterssupply.com/ AAA quilters has really nice fabric and prices are good. I buy my 108" backs from them. They have a few that are wider then that. They too are very reasonable and top notch customer service. If the postage she charges is cheaper she will send a refund