I'm not sure about the brand nymph skin, but something called scudback (stillwater solutions) should be sold at wholesale sports and the hareline equivalent should be at fishtales. I hope that helps!
Never seen nymph skin before but I've been buying a product called "UV Chewee Skin" from Iron Bow fly shop just off of crowchild. it comes in quite a few colors and most of them look very very buggy
__________________ Fishing isn't always about catching fish.
Sometimes you just have to take a deep breath, look around, and admire what mother nature gave us.