Yikes - thread necromancy of a elder nature!
That said, for SP, Yew is still the best answer for wool - You just might need to approach it from a direction other than the Yew Gate.
There's also a number of roving sheep in the woods between Yew and Skara, if you just walk around and look for them.
Remember - shear, THEN kill, as you get more from a live sheep, and then the kill is to get it to respawn.