Wii U Gamepad inspired Retropad build

[Guinan]

Right. So I'm abandoning my full on Wii U Gamepad build. I'm still using the same look and feel of the Gamepad but I want to do too much for the small little case to accommodate. To that end, I am going to scan the shell into my computer to create a 1:1 cad model so I can edit it and create my own Gamepad inspired case on my 3d printer in ABS. I will post the STL files here when I get everything scanned if you all want them. If you already know where to find these STL files, awesome. Let me know, please.

Since I have decided that I can go ahead and give myself more space, I have a unique question that I'm hoping someone can either talk to me about accomplishing it or just talk me out of it because I don't know the feasibility of what I'm asking.

So, the 3D printed extra space got me to thinking if it would be possible to have GameCube and back on this thing. I have just about every maker board out there. I know that NONE of them can play the GamCube. I have one that is X64 based Intel Atom which runs the emulator but it doesn't play it as well as I would like. So I thought: why not just put a GameCube in there? So I'd have RetroPie on a Raspberry Pi 3 for everything and then, turn the Raspberry Pi off and press the TV button and boom, it powers up the actual GameCube motherboard and allows the playing of GameCube ISOs from the same internal SSD that RetroPie would pull.

This build may not be possible, but if it could be done, then both boards would need access to the controls. And I don't know how I wold handle the power. Would powering up one board cause both boards to power? Or could the boards be encapsulated? Would I need two sets of batteries? Can I just connect the Teensy to both boards?

I'm hoping I could do this because I think that it could be wired so that both boards have access to the controls. I'm just not sure if it will work. What do you all think?