I have started working on this project a few days ago when I got all the parts I need. Still waiting for the audio board to come in from Amazon. So far the only issue I have ran into is the GPIO pinouts for the FPC breakouts. There is a few things that I have done differently, as by drilling a few holes in the side for the wires from the sd card and such to run through for a cleaner look.
If you wire the grounds from the speaker to the outer one the headphone jack then the ground from the jack to ground it will let u make the speakers work in,tell u plug into the headphone jack then will switch the ground to the headphones,giving u the auto switch from headphones to speakes