SBC Interfacing Board Design & Development

We have once SBC attached in link below

https://docs.radxa.com/en/cubie/a7s

We are looking for an interfacing board for above SBC with hardware schematic design as well as PCB layout development with your service.

My interfacing board requirements are as follows.
1. We need 16 port USB connection from SBC USB connection ( 1x16 OR 2X8 )
2. We wish to have USB to AUDIO 3.5mm Jack for (16 Audio inputs to send on serial port)
3. We need LEDs to glow whenever a 3.5mm Audio Jack is inserted.
4. provision for 3 LEDs from SBC GPIO
5. provision for 2 Switches from SBC GPIO
6. We will have Power Jack for input Power Supply ( PSU will be external) for example Laptop Charger
6. We would like to get your suggestion on Power adaptor selection to run the hardware. 
7. According to the Power Adaptor make sure SBC and hardware gets desired input power.
8. This hardware will run 24X7 hence we expect you to take care of heating management in hardware. SBC has FAN connectivity. we just have to make it work according to FAN selection.