I purchased the Helium Digital Bluetooth Communicator HDBT-110 which is reviewed at this
link. Works as both a car kit and an office speakerphone for my 8700c. Pairing no problem, sound loud and clear. But best of all, when delivery via CanadaPost was delayed, their customer service was prompt, responsive, polite and helpful.
That is a big selling point for me given the "customer service" I usually have to deal with.
BTW, I have no connection with this company other than a satisfied customer.