Swede's in Woodinville, WA has some in stock. Not a lot, but some. I'd advise getting it now before it is gone if you want it.
I prefer coche tail or schlappen because the Whiting Spey Hackle is nothing more than long fibered rooster hackle. And as sunch it is fine fivered. It neither looks nor behaves like heron, coche tail, or schlappen in the water. Why not get some bue eared pheasant?