i listed all the hardware needed at this stage on the whitearmor forum, i gave you the link in other topic
in that video you can see arduino UNO, but in the final stage i will use the arduino NANO 328, same specs of the UNO but smaller
the mp3 player you see on video is quite expensive and large dimensions, today i got the WTV020, you can read here:
http://arduino.cc/forum/index.php/topic,110924.0.html