I like Whiting 100s. I like the Cabelas Metz packs. Note that of the Metz packs that I have gotten from Cabelas, the size varies a great deal. The feathers in my "size 16 and under" will tye flies that small. But I have also tied some really nice size 12s with them. These packs are cut from capes. There is more variation within a feather from a cape than from a saddle, usually. (Apply the caveats of modern breeding etc...) The butt of a feather might tye a size 12 while the tip is a nice 16 or 18. Some of the feathers from my packs can tye down to size 20 or smaller. I have a variety of capes and saddles from a variety of sources. The micro-sized Metz packs that Cabelas sells are a valued part of my supply. So are the Whiting 100's and saddles. To tye a variety of sizes and colors, I would probably get the smallest-sized Metz pack from Cabelas since it will provide the greatest range of sizes over whatever 3 colors are in the pack that you choose.
Another thing about the Metz packs is that it is more efficient, for me, to start tying larger flies to use up the butts of the feathers and then I progress to the smaller sizes as I work down the feathers and also have warmed up my eyes and fingers. Get some small, ziplock bags (from Michaels, the grocery store, etc...) to keep the left-over feather tips in. That way you can better preserve the smaller and more valuable sizes of feather between tying sessions.
Happy Tying!
Ed