When I purchased my Zumo 350 it came with a free Bluetooth headset so have a good look on line before you purchase.
The headset is a Uclear HBC 100, it has a boomless microphone and has worked great with the Zumo, I have never tried it bike to bike or person to person.
Before the Uclear I was given a set of BT Multi-Interphone, they are a very cheap set and worked OK with a GPS but I never tried them person to person or bike to bike, the interphone set does have a boom on the microphone that is a little inconvenient.
Both sets can be moved from helmet to helmet with the temporary clips they supply and I have just received some extra permanent clips for my Uclear so they can be mounted on each of my helmets, my new Shark Evoline helmet is better suited to the permanent clips than the temporary ones because of the shape of the helmets bottom edge.
Hope this helps, cheers.
Some of the 19 rides in my shed
2014 V2, Snoopy
2009 Wee, Pumbaa the pig
WR450F, The Blue Postie Bike
YZ250N smoker with rego, Stinky.
Yamaha MT09 (FZ09), The Scud missile.
Club Lead not Club Med.
He with the most toys wins.
Out of my depth in a puddle.
Live life on the edge you will see more that way.
Ridding a motorcycle keeps things in balance.
At the end of each trail and at the end of each day history is made.