I agree with
Roufinator
I use the Arduino pro micro, which already has an integrated HID joystick. With an infrared sensor
and an old television remote control I can use it to send any commands to the simulator. Not nearly as chic as your panel, of course. In order to query the states in the simulator (for the LEDs) , you need a program on the PC that reads out the SimConnect interface and forwards the results to the Arduino.
That should be a lot of work.