What is needed for Com/Nav radio's ?

Hello team,

Currently I am almost ready with my Phidgets based autothrottle system.
For extra features I already have the 0/16/16 module.

Could you tell me what I need extra to make a Commradio, a Nav radio and a Transponder radio ?

Also I am planning to builta B777 MCP .
For that I also would like to know which hardware is needed.

Thanks for helping, :)

Gerard Salden
Netherlands