Though not necessary, jig hooks help flies ride hook point up to minimize snags. Slotted tungsten beads allow you to mount larger beads on your hooks.
Cased caddis patterns are great choices for anchor flies. This one will get to the bottom in the strongest currents.
My favorite anchor fly of all. A large (size 10 or 12) flashback pheasant tail with an oversized slotted faceted tungsten bead and lead underbody.