When selecting signal mirrors for myself and my kids I just couldn't justify the weight and shatter-risk of the glass mirrors. I went with the Adventure Medical Kits Rescue Flash mirror at
http://www.basegear.com. This is the same mirror Doug used in his PSP.
Actually, each of us will carry a Ritter PSP (great gear for the $$), but I bought a few extra mirrors for us (and my Boy Scouts) to practice with so the PSPs stay intact. I know ... I'm weird.
By the way, I have a Starflash mirror somewhere around here too. It is a decent mirror. It should do you quite well.
Ken K.