I am going to give links for each part used in this project. You can buy everything from there. You can use Bluetooth modules as I did for the first time or you can use directly the long range HC-12 modules. When you buy batteries bevare of fake batteries, buy Samsung, Panasonic or Sony.
Only for Brainwave User's: I have to notice that I used a ahcked Nacomimi Brainwave Toy, that is made by the same company, but to save time use this headset instead:
If your parts arrived let!s get to work!