I need a electrical engineer for a product I would like to design (bluetooth experience)

I have product idea, I need to fit a mic, bluetooth, battery to last up to 8 hours of talking and a charging unit fitted into the design of this product. I have a pair of Bose bluetooth earphones, and it exteremly small, the charger attaches to the ear piece and the bluetooth and battery is in the one side of the earphones. So i'm sure the parts must be available but I would need it to be adapted to my project. Is there anyway either through an app or through the phone that the device would be able to pick up two different devices like earphone any brand and then still be able to use product that will also need to link to those earphones, so either be able to automatically link to the earphones, or be able to use two bluetooth devices at the same time from a single device? I'm not sure if that's possible?