Pretty sure truenas scale can host everything you want so you might only want one server. Use Epyc for the pcie lanes, and a fractal design r7 XL and you could even escape needing a rack mount if you wanted. Use a pcie to m.2 adapter and you could easily host apps on them on a mirrored pool and use a special vdev to speed up the HDD storage pool
The role of the proxmox server would essentially be filled by apps and/or VM you could turn on or off as needed.
Pretty sure truenas scale can host everything you want so you might only want one server. Use Epyc for the pcie lanes, and a fractal design r7 XL and you could even escape needing a rack mount if you wanted. Use a pcie to m.2 adapter and you could easily host apps on them on a mirrored pool and use a special vdev to speed up the HDD storage pool
The role of the proxmox server would essentially be filled by apps and/or VM you could turn on or off as needed.