I am of the non-schlappen spey hackle camp. It's too webby and 'sticky' for my tastes. Blue eared pheasant is naturally a dun-nish color and makes a very close approximation of the real thing. It also comes dyed in various colors. Another hackle I like is the burnt goose, which has a thick stem and brittle barbs but for some reason I've caught a lot of steelhead on flies tied with these feathers. You have to pick thru them to select them on the supple side with a thinner stem. These come in a broad range of colors.
For smaller spey flies, I use dyed mallard flank feathers stripped on one side. They also come in a wide range of colors, are cheap, and work fantastic. In fact of all the speys I fish the most effective have been small summer speys hackled with dyed mallard - the BEP is too large for these little swingers. I like the black, purple, woodduck, olive, and sedge orange colors - mallard is inexpensive and dyed in tons of colors.
BEP is best but has a very high price tag and is harder to find in the proper sizes and colors.