One of the cool new features of the GoPro Hero 9 is that you can use it as a 1080p webcam. Sadly, the out-of-the-box experience is glitchy and way too unreliable to use for a serious project, but you can fix it with the right setup and more $$. TLDR: Get the media mod and use the HDMI port for better output, take the battery out and power directly through USB to prevent unwanted shutdowns, and use OBS studio to resolve audio/video syncronisation issues.
TLDR: The Coolermaster H500M case supports up to a 240 mm radiator in top-mount position and up to 360 mm in front-mount position, but a front-mounted 280mm radiator is probably the best option for an AIO system.