I've bought from all 3 of these places and been very happy. The better you know your fabric lines, the happier you'll be. Quilt magazines showcase fabric lines all the time. Or, you could see if you can buy a fat quarter (connecting threads) at a time to try out a color or order the smallest quantity allowed to start with to see if its the right fit for you. All of these places have given me excellent customer service. (This is just my opinion.) I order a lot on line for variety and specific fabric. All my blenders come from Wal-mart(Cranston Village is a favorite), JoAnn Fabrics and Hobby Lobby. I have also bought fabric from Elanor Burns and Hancocks in Paducah, KY. But, only their clearance fabric.
http://equilter.com/
http://fabric.com/
http://www.connectingthreads.com/Quilting.cfm
I love Michael Miller, Sweetwater and Moda fabrics. These are pricer fabrics and I usually just buy smaller quantites to mix in with projects I'm working on. (My budget doesn't allow for large purchases.)
Good Luck. I hope you find what your looking for.