I've used my Scala Rider Q2 for the purpose you are looking for. It worked great. I've also used it bike-to-bike with great results. The only advice I have if you go with the Q2 is to look up the modification to cut off the speakers and add a port for headphones. Earbuds are night and day better than the included speakers. Mod cost is about $5.00 if you already have a soldering iron.
EDIT: I just searched for the Backchat Vixen and cannot find it anywhere. I'm finding forum links and reviews, but not where to actually buy the product.
You can get a Scala Rider Q2 Multi-Set for under $175 on eBay that would fill both bike-to-bike and rider-to-passenger needs.
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