My Pandora's Box conversion is complete on the hardware side.
Left: 3TB portable USB3.0 drive, single data+power cable. 29550 games currently installed with 1TB of space left.
Middle: Raspberry Pi 3B+, 4 cores at stock speed of 1.4ghz, 1GB of RAM, external USB Bluetooth 4.0 dongle paired with controllers and keyboard/mouse combo.
Right: 2 x 8bitdo SN30 Pro Bluetooth controllers.
All the above items are held inside the case with 3M Dual Lock, kind of a more hardcore version of Velcro. Each small strip is rated for over 20 pounds of force. Two strips hold the hard drive and Raspberry Pi in place. I split the last strip in two for the controllers. Everything is so solid that nothing budges even if upside down but is still removable in case I need to replace the hard drive or whatever. Controllers will be inside the case for storage when not in use.
Retroarch included a change recently that changed how controllers are ordered. I reverted it and set up a tool that prioritizes the Bluetooth controllers over the arcade sticks. The idea here is that you might prefer using a SNES style controller for older console games so all you need to do is power one up before you start the game and it's all handled automatically.
Soooooooo... who wants to come over? ;) #retropie