I’m looking for something from 4TB upwards.

If you say "harddrive" ... do you mean actual harddrives or are you using it synonymous with "storage"? If you really talk about actual harddrives, it's hard to even find datacenter/server harddrives below 4 TB. Usually server HDDs start with 8 or 12 TB. You can even find HDDs with 20 TB - Seagate Exos series for example, starting at around 360 Euros (ca. 400 USD).

If you're in for a general storage, preferably SSD, that's another issue. There is the Samsung 870 QVO (8 TB) SSD that is often advertised as "datacenter SSD" (so I assume it would run well in a server that is active 24/7), but it is currently available with a maximum of 8 TB. The 870 QVO is at ca. 70 Euros per terabyte (ca. 77 USD) which, in my experience, is the current price range for SSDs. So it has a high price seen from the outside but it's actually fine. It's also a one-time investment.

For selfhosting I'd go with an SSD-only setup.

do any have particularly good or bad reputation?

From personal experience I'd say, stick with the "larger" brands like Samsung or Seagate.