I’m building a G3X panel in my S7 right now too. Jason at Aerotronics in Billings MT is the best at this. They can design and cut the panel itself and they are experts at telling you all you’re going to need. I went to a 3 day school in Kansas City in January on installing the G3X - it was a great confidence builder in doing all your own install and wiring. Worth the $600 for 3 days.