All of the above are good sugestions. But I think I know what would work the best for you. I agree with Jon (who makes some of the best electronics available for our GoldWings) that earbuds are the way to go. My wife has complained about noise in her helmet and poor sound quality since day one. Even with EdSets (which many of us think are the best going) she was not happy and would turn the sound all the way down to her helmet.
A friend told me to see Marilyn ( owner of Now Hear This) while I was at the Ft. Worth IMS a few weeks ago. Marilyn has designed an earplug that is unique. It is soft and flexable so it conforms to any ear and is small enough that you really do put it IN your ear. Marilyn also makes an adapter that lets you plug into the standard Gold Wing plug and then plug in the earbuds. This way you can use the helmet speakers if you want or plug in the earbuds and still use your helmet mic. They fit so well my wife used them on the ride home and even with her regular speakers in the helmet said they were very comfortable. She commented on how much quieter they were and she actually listened to the radio all the way home.
She does not have these listed on her website so you must call her to get the information. Did I forget to mention she is an Audiologist with a full time practice in Miami? She knows her stuff and has an excellent reputation with those that know her.
thickness: The J&M's are maybe 3/8" thick? while the IMC is about 1/8" (memory estimates only, but the IMC is much thinner.)
sound quality: it's like comparing a set of high quality home stereo headphones (like the Denon 950) to a $5 transistor radio (remember those?). Of course, you are still bound by the limits of the onboard sound system . Speaker placement is absolutely critical, of course. You may have to use the bike's equalizer and turn down the bass, too. The IMC is the winner.
I did get an open face IMC and after i installed it, the "boom" on the mic is very weak. I lean forward and it moved with its own weight abt 4" away. Also how did anyone mount the plug end to the helmet?