Here are the links to the products mentioned (some are affiliate links):
-USB to DVI/VGA/HDMI adapter: http://TDM.fyi/usbvideo
-J5Create USB-C to quad HDMI adapter: https://www.bestbuy.com/site/j5create-usb-c-to-4-port-hdmi-multi-monitor-adapter-silver/6381214.p?skuId=6381214
-BlackMagic Design Decklink Duo2 Card (must be supported by software; won’t show as outputs for the OS): https://amzn.to/3aVYmti
-Xcellon Little Brother Thunderbolt 3 enclosure (not shown in the video): https://amzn.to/3htusPH
More information about eGPUs: https://www.macworld.co.uk/feature/mac/best-egpu-mac-3673105/ https://egpu.io/best-external-graphics-card-builds/