Quantity   Component name
10 × MAX7219 8x8 LED matrix board These are readily available on places like eBay.
1 × Arduino or other microcontroller Anything which can communicate via SPI.
1 × 5V switching regulator A linear regulator cannot be used here due to the currents required (3A is a reasonable limit).
1 × 3D printed supports You can probably make these using other methods, 3D printing was the easiest option for me.