I've got ALLOT of experience fishing rubber worms so i'll toss in. I'd offer that you shouldn't be in too much of a hurry to try to mach a 8-9" rubber worm. There are times where these are best but i've often found that a 4-6" rubber worm often outfish's the larger cousins. When fishing especialy gets hard, I my GO TO wormis a 4" ringworm ( see the worm on teh left in the last pic in the hard worm instuctions for a sample). Not tons of action or huge in size but deadly. If you really want to try to imitate the longer worms ( without actually fishing a rubber worm on a fly rod), you'll need to use long saddle hackles or bunny strips (for the most part). Each have their ups and downs. Saddles are light and easy to cast and give you moderate action but foul easy on the . Bunny stripps tend to weigh like wet rope to cast but give better action.
Remember, the fun is in the process, not the results!