I bought a Synology DS1621+ last year that I've been slowly building out as my homeserver. With the main focus obviously being storage it is a fantastic NAS, but I've found many of their other packages are also suprisingly solid.
I started out migrating my DHCP, DNS, and directory services over to their packages, & then spun up a couple VMs in their Virtual Machine Manager (really just QEMU/KVM under the hood). Eventually I decided Docker would make more sense than running separate VMs for everything, so I began to learn that. So far I have Plex, Pihole, OpenVPN & a few other miscellaneous services like LibreSpeed running in Docker.
The only real challenge with the Synology has been on the network side. They are definitely aimed at the small business/home user market & don't expect a complex network topology. Getting tagged VLANs working properly was a chore, especially in conjunction with the virtual machine manager...and even moreso, integrating that with Docker so that I can assign IPs to individual containers or isolate them in separate VLANs. All in all it wasn't THAT hard, but definitely took a couple weeks of research & banging my head against the wall to get it all running smoothly.
The only downside with the NAS is that it can't transcode in Plex due to the Ryzen cpu. I don't really have any need to transcode currently, but eventually I want to get a NUC or something along those lines to better serve Plex (& possibly the whole Docker environment). Maybe build an ESXi host? We'll see...
For my network I mostly run cast-off enterprise hardware. Fanless Cisco compact switches with PoE & full L3 images are fantastic little boxes that are relatively cheap & feature rich, assuming you're familiar with IOS. Eventually I want to add a 10Gb NIC to the Synology & upgrade my network backbone along with it...hopefully prices come down on these by then:
https://www.amazon.com/Cisco-Catalyst-3560CX-8XPD-S-Multi-GbE-WS-C3560CX-8XPD-S/dp/B011Z74JP8