Hello Peerobo,
i know it’s not helps to you much now, but I’m just released my project, what can helps you if you looking something like that. Only Issue is that is in development phase and prototypes can be here not sooner in 5 weeks, approx.
if you are interest, see link here for more details:
http://forum.khadas.com/t/extension-board-for-vim-audio-spdif-usb-gpio-new-development/634