Hi,
As mentioned earlier I will ask my friends for your onsite projects.
And as per you HW requirements, it looks like only 5 UART are required (if HW flow control required let me know), there are readily available boards(around 20$) which can meet your requirements.
Can you share your complete I/O details?
About us:
We have 10 years of experience in Product development.
Micro-controllers we have worked on PIC, STM32, PSOC and AVR.
Development kits and instruments available for testing purpose.
For PCB designs we use KICAD.
C#, LABVIEW, Python for GUI, Controlling or Datalogging purpose.
Thanks and Regards,
Santosh