Dave, how you doin' Bro? I have Ostrich herl in many different colors, but for scuds i usually use grey. A rib is totally unessesary, but you can put one if your worried about durability. I spose it does help, but if you tye the shell back down good and tight, your fly will be druable. And anyway, if you catch a few fish, and have to tye on another fly.........that's not the end of the world. Just bring plenty........no biggie. To me what's more important is getting enough for a fishing day tyed up in one eve. asap, so i can get on with tying what's a lot more fun and important, Salmon Flies. Go head and put the bead on them though, they sink a "bit" better/faster and are much more attractive to the fish. mark.....