Fish can be on the larvae and pupae too during the October Caddis hatch, so it would be good to have some of those, and some drowned adults couldn't hurt . Dropping a pupa off a dry can also be a good thing. The females will skitter around on the surface dropping eggs, so, in addition to the EHC and Stimi's, you might want to add a skating steelhead pattern too, since they're around, you might want the stronger iron of a salmon hook.
"Nymphs" imitating the larvae after they've eaten their way out of cases:
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and this one:
Pupa I would want both weighted and unweighted versions:
See Han’s Weilenmann’s nymph above, and modification for pupa. You could also use a LaFontaine’s Deep Pupa weighted with a black bead head and Emergent Sparkle Pupa (Orange body, brown head size 4-6) You can google for patterns, but here’s an easy OC variation:
Virtual Flybox :: Patterns :: October Emergent Caddis Pupa
Tabou Caddis, tie with Orange body, brown head for OC in larger sizes 4-6
The Tabou Caddis Emerger - Simplistic Buggyness Using Two Materials - Global FlyFisher
X Caddis 6-10 google
Stimulator 6-10 google
And for a steelhead version of an October Caddis Skater (crystal caddis) 4-6
Surface Flies for Steelhead by Dennis Dickson
LaFontaine’s Diving Caddis orange body brown head 4-8 (google)
Hope this helps, it's a great hatch to fish!