About the Dragon, just got mine in from Directron 2 weeks back. Looks like I was just in time!
Anyway its an awesome case, and it cost me ~$60 + shipping. I'd keep looking to see if you can still get one. As I recall the Matrix is a little smaller.
Anyway heres what I did with mine:
Double core fits great! Though I still need to clean up the edges, I'll take care of that when I get my new shroad finished.