Yes, Black Cat Creations are still in business. I know that you can find the patterns at www.itsastitchonline.com.
We did a t-shirt project with my daughter's troop several years ago (she's 24 now), and we used whatever crayons were in the troop box. We had a bunch of children's coloring books that we tore the pages out of, then outlined with different colored permanent Sharpie pens. If you don't want the fabric to slip (as t-shirts do), place a piece of fine grit sandpaper underneath the area you are coloring.
Once you've finished coloring in your projeft, place a layer of newspaper or brown paper bags on your ironing board, then place your colored fabric on the paper. Cover that with a pressing cloth, then press with a medium hot iron. The heat sets the dye in the fabric while it melts the wax away. It also sets the Sharpie ink.