I voted turnkey no regrets.

1. i only use as a NAS / backup
2. i run 90% of my VMs, containers etc on NUCs (I run one VM on the synology for proxmox backup server)
3. i see the cost of the synology more about paying for their backup software than paying for the hardware

i own a couple of the cheap random brands like this

i think my last unmanaged 6 RJ45 port one with 2.5gb poe and 2 SFP+ 10G ports cot $90 (USD) in sept.

They are great value for money, so are the managed ones. I used it for a dedicates network for a ceph cluster (its sort of hidden in this shot on the rack shelf to the left of the ubiquiti POE switch https://gist.github.com/scyto/76e94832927a89d977ea989da157e9dc

Plex kernel is optimized with fixes specific to proxmox scenarios. For example it is currently impossible to do my setup https://gist.github.com/scyto/76e94832927a89d977ea989da157e9dc on Debian or Ubuntu without compiling your own kernel, which then would break ceph…. The proxmox team do a lot of due diligence on their kernel, patches etc. for your docker scenario consider using VMs as your docker hosts. Lightweight VMs don’t add a lot of overhead. Something like this https://gist.github.com/scyto/f4624361c4e8c3be2aad9b3f0073c7f9

Nice! Consider some set back adapters for your PDU, then you can make sure the PSUs don’t stick out. I used some in my slightly larger rack https://gist.github.com/scyto/76e94832927a89d977ea989da157e9dc I think they are useful to stop plugs getting snagged…