DiskStation DS1821+

Same boat here. DS1821+ has yet to let me down with dozens of Docker containers and other servers running.

Only if you also use Synology photos like OP mentioned. I used to run on dedicated box, but have moved it back to my Synology DS1821+ since remote ML works so well that the 1821+ can handle everything else and has most of my storage. It took me hours to figure out how to fix this with targeted SQL q

Sure! Usage and risk estimation is totally yours 😀 Bear in mind that commodity NVMEs (and SSDs and even HDDs) may not be able to flush all data from DRAM to storage/hardware in case of power loss and you may loose and corrupt your data this way. You estimate risks yourself, but ECC is important for

I started with a DS920+ and now I have a DS1821+ w/ DX513 expansion plus a DS1618+. If drives were cheaper I'd probably have less and just upgraded the drives in my DS1821+.

I moved from plex and other tings running on an old windows pc to a synology ds1821+. If I had it to do again I'd do the same. For me the killer app is SHR allowing disparate drives to give redundancy. I love the rich user community - I had my apps all install on a local ssd before I added the cache

Synology DS923+ or DS1821+ would be perfect for you. Easy setup, great for 4K streaming, and room to grow beyond 40TB. Their software is basically plug-and-play. No building, no headaches. Just pop in drives and you're rolling!