bluetooth eeg

Hi,
I have been tinkering with some components to make an open source bluetooth
eeg.First question I have is:

 Are there any examples of a bluetooth eeg already built that include
everything I need to build from components?

I have started playing with a design of my own. I want to use the dual
channel fm frontend and connect it to a pic microcontroller and bluetooth
serial module. My next questions have to do with the design of the device:

What adc sample rate is sufficient for eeg signals?

Would it be a good idea to use an automatic gain control circuit instead of
a potentiometer?

thank you.

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