If you're willing to spend money on rack-mounted gear you definitely have options, and what you get sort of depends on what you're interested in playing with.
A lot of homelabbers (and even some small businesses) go for Proxmox as a virtualization distribution. I don't use it myself, but IIUC it's effectively a Debian distro packaged to run KVM/LXC, with support for things like ZFS, Ceph, etc. It has some form of HA, an API used by standard open source devops tools, handles live migration, etc.
So buy some used rack-servers on Ebay (or new, if you're ballin'). A lot of businesses sell their old stuff, so you can pick up a generation or two out of date for a good price. If you want to do fancy stuff like K8s, Ceph, etc you'll probably want at least three nodes, ideally more, and a bunch of disks in them. Networking gear is a sort of pick your poison thing. A lot of people love Ubiquiti gear; a lot of people hate it. TP-Link is another that's good and budget friendly. StarTech sells smallish racks (including on Amazon), if you want to start there.
It won't look exactly like SoftIron's HyperCloud or Oxide's Cloud Computer, but you can certainly get pretty sophisticated.
Not sure if this answers your question, but other great spaces to explore are the 2.5 Admins and Self-Hosted podcasts.