I've got one box. Just one. It's built in a Node 804 case with 8 18TB hard drives, an HBA, an RTX 3080, and a Ryzen 3900XT with 64GB of RAM. I've sunk well over $2000 into this one box.
It runs my full media suite (Emby, the *arr suite of software, Jellyseerr for request intake and management) and a little left over for when I feel like spinning up a Minecraft server or something
They are recommending the 9600-16i because it is new and available. The 9400 series is older and no longer being manufactured. Anything available is either used or new-old stock.