If not, Collins carries what he calls Tailing Packs. Not necessarily spade hackle, I've seen them called scapular feathers, but they're good for flies up to a #8. I bought a bag of ginger, brown, grizzly and dun years ago and they should hold me for a long time; think I paid $5/bag.
About the only thing my old Metz necks are good for anymore is the spade hackles.
Regards,
Scott