Here's my 2 cents worth. My system is similar but I don't have as many cameras. I bought refurbished as you can really trust it knowing they fixed and definitely tested the equipment.
Suggestions:
- Get a tower. Running 24/7, it's easier to keep things cooler. Make sure wiring is routed inside to allow for good air circulation. I started out with a small form factor and ended up repurposing it and bought a tower.
- Use a secondary purple drive to save images. I tried using my 12tb pr2100 cloud drive but Blue Iris seems to like a local drive much better. With that many cameras, you definitely want to make it as easy as possible for the cpu.
- You don't need SSD for the main drive
- Because of the heavy power consumption, I added an EVGA bronze 700 B power supply. Runs very quiet.
- The more RAM the better
- Have BI run as a Windows service upon startup. Don't run the program unless you need to interact with it. I believe having the program visible on screen draws more from cpu and ram.