Greetings,
I'm currently using the NoiseHush NS560 (
http://noisehush.com/stereo-bluetooth/ns560-clip-on-bluetooth-stereo-headset) and it works great. The best parts so far are that I can increase the volume beyond what my iPhone will do, and I can use whatever headphones I want. I have found that in-the-ear earplugs are best for me with my bad hearing. Kills the wind noise too. I know its not legal in a lot of places, but I can't hear anyway! It also works as a 'dongle' to play anything it is synced with through the aux on the Harley's radio. Requires a cable, but a very short one with a close mount just about anywhere. Really cool possibilities!
I like your idea of putting everything together with the Sena SM10 when I'm not using the CB. I only use the CB on group rides, so the SM10 will take care of 95% of my needs. I'll get that $20 headset adapter from Spoiled Biker that you mentioned and I can't imaging what else I could need!
Thanks for keeping this going. This Bluetooth stuff is kinda like working a puzzle with infinite ways of putting it together.