OP here - since there seems to be some interest on the details I will try to answer them in as much detail as possible in a longer blog post. I already wrote about the network setup[1]

The server is a Dell Precision T5610 (20 physical cores, 64GB memory, 4 Samsung Pro SSDs and quad gigabit NIC additionally to the internal one) and a QNap TS-531X with Seagate IronWolf drives. I would recommend against using PIs at this point, see other comment[2].

Right now all services are running in docker in a dedicated VM on VMWare Workstation. The server also hosts a full work environment I can RDP and SSH into, depending on what I do, when I am traveling only with my iPad Pro (RDP because my last job involved a lot of Java for which I prefer IntelliJ). At some point I should likely migrate to vSphere, but I had the workstation license already and it was quick to setup.

[1] https://screamingatmyscreen.com/2018/7/building-our-home-and... [2] https://news.ycombinator.com/item?id=17966264