Just about anything is OK for a server, I use whatever hardware I get from work thats being decommissioned.

The biggest limit I see is the ram. Depending on what you spin up and how, it’ll be the tightest budget per service.

Then tag with [CBH] as required.

Proxmox.

Each service becomes an LXC. Docker containers can be migrated to LXC, or be contained within an LXC dedicated to docker.

Running out of processing power? Add another server, add to a cluster, and migrate services (LXC or VM) over.

Having run Fedora, Debian, Ubuntu, CentOS, RHEL, slack, even Oracle Linux - Proxmox is what I run for myself (and some clients).