The main thing I look for at buying fabric is the quality and the thread count. Actually I'm not counting - but after a few years of quilting I can see it and feel it. Because I only do handquilting and not patchwork the thread count is very important to me. Less than a 60 does not work for me, the quilting stitches will "fall" between the threads. Therefore I look for a higher on. 70-75 works best.
I love to use P&B Fabrics, Moda Bella Solids and Quilt Gate from Japan. Fortunately I can get them from our wholesaler where we buy for our Online-Shop - but the LQS also have it.