Are you looking for Fly Tyers? Have you tried Facebook and similar social networking site? I myself just searched the term "Fly Tyers" in to the Facebook search bar and it produced hundreds of results. Facebook business pages like Fly Tyers are always welcoming your business and are often sole traders who will produce great quality work for you, you can also connect with them on a more personal level, assuring mutual benefit.
If you're after something to actually make you're flies with, eg. Fly Clamp, then just heck out eBay or local classifieds!