My recommendation is that you not put a large number of hard drives in this machine. Instead, buy or build a separate NAS for data storage, and put fast networking into the machine instead. You will thank yourself a few years down the line when a single drive has a fault, or you decide to add additional storage, because you won’t have to take your server offline and slice your hands to ribbons accessing the drives. Probably the best decision I ever made in my homelab was to get a Synology NAS with hot-swappable drive bays. They are compact and easy to maintain. (I do wish they had faster networking built in, but you can get expansion cards to enable 10G if you have it.)
If I were rebuilding my media server today, here’s what I would do:
Newest possible Intel i5 processor with onboard graphics
2 TB Samsung 980 Pro NVME (or SSD)
Any good Noctua-branded CPU fan
Any good gold power supply
Any compatible motherboard
64 GB RAM (Your media server won’t need this much, but if you ever want to install any other VMs or containers on the server, it’s nice to have a large pool of RAM available to make that happen.)
A two-port 1gbe network card (for link aggregation)
I would not put a discrete graphics card or any spinning platter hard drives in the machine. For the OS, I would install Proxmox and then create a virtual machine or container for your media server. Since you are using the graphics on the CPU, pass-through of the graphics will be much easier this way.
I would direct any additional funds to an external NAS and a UPS that can tell the server (and NAS) to shut down when power is interrupted.