If a Comms system is an intercom system ??? don't muck around. I've been on the road on a bike for 40 years and tried heaps of em that all went in the bin except one.
Autocom is the go and never fails

http://autocom.co.uk/

You can run anything you want through it and at any speed clear communications with your pillion. Have talked to my pillion at near 180MPH on my Blackbird without a problem.
I currently run my GPS, Mp3, UHF CB and phone all without a problem and have done for years.
My one hint is, get the Autocom hamburger with the lot.
The wired up one not the bluetooth. So what that you have to hook up, your using the best. You never have to recharge. You cant lose it. No one can steel it. Get the best and you never look back.