I have been buying from www.equilter.com and www.keepsakequilting .com for years. Equilter doesn't have a catalog but their website is very good with large images of the fabrics and a design board so you can see your choices side by side. Their color reproduction is excellent.They have a vast selection, and their service is great.
Keepsake quilting has a wonderful catalog. They too have accurate color reproduction and their fabric medleys are great. Very good service too.