Hey friend, you’re aiming for a setup very close to what I run. Some lessons from my fumbling:

• Get a NUC and install HASSOS on it for Home Assistant. Treat it like an appliance and leave it to do it’s thing.
• I run Frigate on a separate host with 2x Coral USB TPUs processing 5x 4K cameras. It sits at about 20% utilization.
• Check out Simply NUC and UCTRONICS for rack shelves for NUCs and Pis. If you have other random hubs you want to rack check out this Etsy store: https://www.etsy.com/shop/Print3DSteve
• I highly recommend a NAS for media and other storage. I have a Synology RS819 and it’s solid for this, but I just bought a used Dell R720XD that I plan on loading up with drives and installing TrueNAS on. I’d check out used Synology options on eBay for your use case.

Given your low power consumption requirements, I’d probably look at something like this:

• 1x NUC for HASS
• 1x NUC with Coral TPU for Frigate + other apps
• 1-3x Pi4s or 5s for other random apps. I run mine using PoE hats to my UniFi gear.
• 1x Synology rack mount w/ 5400 RPM drives (lower power consumption).

If you want to do any AI/ML beyond Frigate, you’ll want a desktop GPU in the rack. I still haven’t found a good option here. I’ll likely get a rack case that works with desktop hardware and throw a 3090 into it.