I started a cockpit build a couple of years ago, but decided to go bespoke rather then buy any instruments at all. I started testing with a small panel incorporating as many instruments and controls as I could cram into it, here’s a picture. It’s powered with an Arduino Mega communicating via Ethernet to the computer.
I stopped though when I got this working because I was really unimpressed with the API that X-Plane 10 provided. If they’d allow the X-Plane parameters and control data to pass via XML or JSON instead of their own warped serial data definitions then it would have been much simpler. Anyway, that might have changed now and I’ll need to get back into it since I’m being inspired by your videos and I have plenty of thoughts on how to improve it. And I must say that flying with any sort of panel is much, much better than using keyboard alone.