I'm trying to get the front half of a renegade. I'm using brown neck hackle for the back end, but don't have anything that works right for the front end in white. I made 3 so far. One with white deer hair, one with natural mallard flank, and the other with a white CDC feather. All of them look odd, but I'll fish them anyways.
Wish I could help you! Was thinking perhaps you were tying streamers or saltwater patterns. I use a lot of white neck hackle, and buy the strung stuff, but don't tie many dry flies. Most of the tying I do is for LM bass or Striped bass.
In addition to the shops already suggested, you might give Feather Craft in Missouri a look or J Stockard in CT. I've purchased from both & never had any issues.
Good dry fly hackle has become quite expensive unfortunately.