I just got the Westone UM-1 earbuds, they have noise dampening about 25 decibles and stereo sound. The wire is braided (hopeully this is stronger than other set-ups) and wraps over your ear. Fits well inside a HJC helmet.
We are planning our big trip this summer and I am going to use a post amplifier with two ports (for myself and wife) from my Garmin 550 with the XM antenna. The post amp, I haven't decided , either wired into bike 12V system or just use some AA batteries. I've decided that microphone systems are very annoying unless full helmets, and we can always give handsignals when we want to stop, restroom, etc. Just want some wind noise reduction and good music. With the Garmin, I can (1) bluetooth the phone to my 12v outlet, see incoming calls, can't answer back, but can always see who's calling and decide to stop or call back later. (2) Run the XM and traffic and weather radio, or listen to the SD disc with pre-loaded MP-3 songs, and (3) hear "Simone" - our gal inside the Garmin 550 tell us we missed the turn!
P.S. SSG Bean - waiting for my seat to return from Russell Day Long, and hopefully by end of month we can hook-up (4 of us) for a short ride.