FreeBSD as edge router with pf, VNET jails, and bhyve — single server or mini PC cluster?

Hi everyone,
I am planning to run FreeBSD as an edge router using pf for NAT and filtering, with services running inside VNET jails (DNS, NAS. Etc) and bhyve VMs on a single host. Storage will be ZFS across 4 HDDs in mirror configuration.
I have access to rack space with proper cooling, and currently deciding between a single rack server or multiple compact machines as a small cluster.

A few questions:
Is running pf NAT, multiple VNET jails, and many bhyve VMs concurrently on a single host a stable and recommended setup?

Realistic RAM recommendation for this workload?

For someone wanting to learn FreeBSD internals deeply, bare metal or Proxmox?

Single powerful server vs small cluster — which approach makes more sense long term?

Background: network engineer with experience (Juniper, Cisco) in ISP environment. Comfortable with CLI and low level network configuration. Primary goal is learning FreeBSD properly, not just using it as a hypervisor wrapper.
Thank you.