Bluetooth Adapter

I have a G4 PPC (Sawtooth) in my shop for simple web searches and listening to music. It's older, but works great for these purposes. I'd like to add a USB bluetooth adapter so that I could use either BT headphones or a BT speaker throughout my shop. What kind of USB adapter should I be looking for that would be compatible with all of the above? Or will this not work at all? DB-120? Other?