No fly shop I know of. Since I am a computer geek during the day I have access to lots of them. They are used to package hard drives and ram for computers. Will look around at work and find one for you if you would like.
Will even send you a sample fly to get you started if you like. Just send me a PM with your address and I will get one out to you. They really work well and strips from those bags really give the fly a nice opaque chironomid look.