I just refurbished an old i5-2400 system with the following spare parts i had and planning on 2-4 2MP PoE Cameras.
Intel Core i5-2400
16GB of RAM
180GB SSD
2TB Storage (3x 1TB HDD of a iRST Raid 5)
Win10 Pro 64bit
RAID Supported MB
Basically an old system I had laying around and spare 1TB...