I use reed material from .010 to .015 in thickness. I make reeds from mylar, duralar and styrene. I like the sound of the styrene, but it's not as durable as the mylar. I buy styrene from the local hobby shop. Model builders use it.
I buy mylar from Hobby Lobby or Walmart. It's sold as quilters templates. I've made reeds from the clear plastic that baked goods and pastries come in. I've even made reeds from the side of a 2 liter Pepsi bottle, but it's a little on the thick side. A few stokes on a hand sanding block with 220 grit paper will thin them right down.
Feel free to PM me if you need more info. Dale