I need a circuit (Teensy 3.6, screen, MIDI, etc) - Hardware DAW

I need a circuitboard designed to connect to connect a Teensy 3.6 to a screen (ILI 9488 SPI) and various other peripherals and four expansion slots. An image is attached of what it needs but it has no expansion slots. The attached image shows to what the Teensy needs to connect but the wiring may not be correct.

https://www.lynxwave.com/electronics for an overview of the project but a lot of that is old information.

I am tired of working on the hardware for this and want to focus on the code.