I use the Chatterbox GMRS X1 models rated with a 5 mile range. They helmet mount, have a load of options and are VOX or push button activated. Stereo earphones and mic all fit inside your helmet. Work very nice except if you have a loud/noisy machine. My 400EX with a Big Gun keeps the channel open all of the time unless you turn the VOX down until it's basically unusable. I'm going to the push button activation, or sport headset next time out.

When I was looking, the HJC/Chatterbiox site did not even list their new GRMS X1 model. I found it by accident on this web site from Miami:

http://www.accessoryinternational.com/chatterbox2.html

Ordered 2 units from them and they are great if you can work out the noise/VOX issues. The units are on the very expensive side though.

Also, I agree that the rechargable battery is not the greatest. My issue is that they have a very small wire and plug on them that makes changing them out hard. Wish they had the slip in type of rechargable battery like my Cannon Elph digital camera. They do provide you with 2 batteries on the X1 so that helps