hekp me build a device!

Hello. I will need the experience of some hardware doctors in this!
I need to make something from a bluetooth headset, or from its parts: i must reduce a bt headset to the following piece :
1. bt chip+
2. baterry+
3. 2 pins for the speaker!

I will need to strip the microfone off, start button, volume buttons, leds , everithing!!
I need to end up with a device that will pair with bluetooth phone, and receive the audio signal from it, and send it to pins to wich I will attach a small speaker! The whole ideea is that I need to build a this device, wich will be very very small (max 1cm x 1cm x 1cm) without the battery, and will work in a wet enviorenment!! The problem with the water i will solve by putting everything in sylicon !!

So any suggestion???
1. what bt chip i use??
2. where i get some docs of it?? (pins, etc)
3. what does a bt chip need to work in there conditions?? (auxiliary parts or chips???)


If there is a hardware section please move my post!

I have attached a logical scheme for better understanding! In the yellow part is speaker wich is no problem. the core is the cip with ?other? component!
If I could find a chip that works only power from battery and line out to speaker, and it does not need anymore parts (black rectangles in scheme) it would be EXCELENT!!!!