Mike,
I’m sure that the ‘type’ of wool you found would be fine for fly tying…
But, I do lots of art shows and events and there are folks out there who raise animals (goats, alpacas, llamas, sheep, rabbits, plus some odd ones) specifically for their ‘wool’. Most of it is ‘hand spun’. Lots of this ‘high grade’ or ‘high end’ or even ‘high quality’ wool is very pretty. It’s also incredibly expensive…couple hundred bucks a ‘short’ skein isn’t uncommon.
I use lots of wool in my fly tying…I’m on a crusade to eliminate dubbing wherever I can (personally, not universally). I like wool because it wets well, comes in a wide array of colors, and is very versatile. ‘Unspun’ long fibered wools make great streamer wings.
Black wool is black wool, though. Once it’s on the fly, no one, least of all the fish, can tell a piece of wool from a $100 skein from one from a $1 ‘bargain-price reduced to clear’ skein.
The ‘cheap stuff’ works just fine for fly tying…ANY yarn store, or even the big box places in their sewing section, will have wool yarns. These are cheap and work just fine.
Now, that being said, I do have some hand spun exotic wools in my materials…usually short pieces that were gifted to me from the aforementioned wool artists who know of my passion for fly tying…I’ve even traded some of my own artwork to get some of it…I have a hard time resisting when the colors are unique.
As far as the yarn you found goes, if they have colors you like and If you find doing so aceptable, you might even be able to talk the manufacturer/distributor out of some ‘samples’ (they will sometimes send you a small length of each color…plenty for a lot of fly tying).
Buddy