Mat Magic is no longer made. However Lion Products carries the Everest brand of mat and frame decorative products. They are similar. Pete Bingham [from the UK] was involved in making them. They have 6 pastel powders, and also ruling pen inks. They are available in the US from Tech Mark, Inc. [info@Tech-mark.com]
Mikki Kavich, Linda Wassell and I all demo'd these for Lion / Tech Mark at the WCAF a few years ago, and they worked well.
A trick than Linda suggested, [and this works for the Everest Powders and regular powdered soft pastels] is to take a razor blade and scrape just a few pieces of grey soft pastel powder, into the powder on the mat, then blend. [I use a foam brush.] The greys really add depth. I think Linda has a set of 5 to 10 grey soft pastels she just uses for this.
And I have found that, even if you powder your own soft pastels, a combination of more than one color works best. Just looks better in my opinion.