According to some of the trout fishers out here on the left coast, the most effective "flies" are plastic beads in several colors, toothpicks to pin them 3" above the hook, and corkies to suspend the rig and act as a strike indicator. So for a few dollars, a plastic case of some sort to hold the beads, toothpicks, and corkies and you're a fishin and according to them a catchin a heap 'o steelheads.
Seriously, I never fish beads or with strike indicators for steelhead. Presentation and fly size related to water depth, speed, clarity, and temperature is far more important the specific pattern. Heck, steelhead have been known to attack/strike bobbers, ends of twigs hanging in the water, and yarn that has been lashed to a hook. Just pick flies you have confidence in and learn how to present them on a controlled swing, Do so and you will catch your share.