Some short updates:
1. The Matrix PCBs arrived. I will post some Images here, when I soldered one.
2.The Layout for the Main PCB is ready! I ended with a pin header to use ESP-01 Modules for the connectivity. Here some nice renderings:
The front LED side with five LED PCBs. Here in red
The Pack with all the LED control Stuff, an STM8 Microcontroller and a pin header to add wifi with an ESP-01:
Like This it should look with an ESP-01: