Sorry to take so long to reply!
While I haven't personally used faux fur, I've looked around, and the site that seems to have the best selection of colors is fursuitsupplies.com. Samples are available, too. Unfortunately, they always seem to be out of stock of a lot of their colors.
Another option to look into would be dying the faux fur. There are tutorials out there. Mainly it would require a dye formulated for synthetics. This is a more messy, advanced process, but could result in the best results for matching colors.
I wish I could be more help!