as the move came out pretty pricey I have built one by myself:
It runs very well - I am having problems with the oute power down of powerbanks. The speaker uses to less energy when booting up. Kickstarting it with the power cord helps. I will get one from Mi later today with a low power mode to fix the problem.
Here is my how-to: http://tiefenthaler.name/symfonisk/en