Consider a refurbished USFF business PC.
https://www.ebay.co.uk/sch/i.html?_nkw=usff+pc
A unit from any major brand will be good and there are i5/8gb units available for well under £100 that will happily shunt 4K video about. Plus they have the advantage of coming in a nice case, lots of ports, included storage, etc…
Honestly any parts you buy today probably won’t be much good in 30 years.
Did you know the world naïve is written backwards on your water bottle?
Three HP ProLiant servers running ProxMox cluster. Each box has a VM for Portaiber, as well as mismatch of VMs running Home Assistant OS, OpenWRT, Ubuntu, Windows and Debian, along with a Windows file server that connectes to four cheap NAS running Ubuntu LTS with a combined 20 mismatched hard drives by iSCSI and borgs them together with Storage Spaces.
It’s a fucking mess, if I’m honest.
I used Kodi with a Jellyfin plugin for media center duties.