This is something I've been trying to achieve for ages and it's just not out there.
Bike based mesh network with multi bluetooth connections, eg, 2x headset, 2x phones/gps/music and aux 3.5mm audio jack. all controlled via login from phone.
Able to have private intercom and group with music shared or not and.. have radar come over all :)
Helmets only really need 3S Bluetooth Headset (with battery add-on pack).
The SC-HR-01 Handlebar Remote that talks to the bike unit not the helmet. And the SC-WR-01 Wristband Remote for the passenger to use, again talks to the bike unit not helmet.
And bike mesh a raspberry pie with a few fly leads for aerial, aux and power.