Synology is pretty stable and really well professional usage, QNAP
lets you pimp and tune or pain add more other hardware on top
as I see it, but a small old use HP server is also a budget solution.
I have used an old HP Proliant mini cube with an Intel Xeon-E 1231
and 16 GB RAM / 16 TB (4 SSDs) together with Openmediavault.
Base model for ~200 € plus 30 € CPU and 50 € RAM and it was
running for a really long time together with dual 10 GBe cards
for ~40 €! So if money will be point, it could also nice and long
running.
But now I am looking on a MacBookPro and QNAP offers some NAS
boxes with thunderbolt 4 and two PCIe slots and on top such many
things to tune it will be then less or more my next option.
2 x M.2 NVMe´s for caching
8 x HHD/SSD´s (2 x RAID5 or one RAID50)
Dual 10GBe Network adapter with 2 x NVMe`s (for caching)
USB Port for Google coral (QMagie App)
USB Port for an external RDX drive for backups
Up to 16/32 GB RAM
4/8 Core CPU for running much Apps services
(Mailserver, S/FTP, Webserver, Mediaserver, LDAP/RADIUS server,
Backup for Mac)
At Speicher.de you may find out how much RAM in real you could add to your NAS. Often it was said 4 or 8 GB RAM only and
in real you could add 16 to 32 GB RAM. Perhaps good to know for running
much services for the entire LAN on the NAS.