I use Kona black and haven't had any fading or bleeding problems.
I've bought it from Joann's and from Fabric.com and I can't tell any difference in the quality between the two. I don't think Kona comes in different qualities, it is the same fabric as far as I know. Just make sure you're getting Kona and not one of the other brands of solid fabric Joann's carries - they DO carry other solid fabrics that aren't Kona and sometimes they're mixed together on the shelves.