My "server" died. Looking to go rack-mount now. 21.5 Promox suggestions?

My "server" -- and by that I mean a re-purposed desktop with a boatload of SSDs -- just died. I'm not sure if I'm going to be able to resurrect it and I thought in parallel I would look into finally going rackmount. I've a 15U 21.5" deep StarTech rack and I'm curious what folks here would recommend for that depth for running Proxmox? It'd be nice if it were power-efficient as possible. Not super noisy might be a consideration too but I'm running cable to locate the rack in a quiet corner of the basement so perhaps not a huge concern.

In a few months I might pick up a handful of additionals and do a Proxmox cluster.

Appreciate any advice y'all might have.