My Nostr project nostrfy is probably the relay server software you’re looking for:
https://github.com/iqbqioza/nostrfyIt supports most of the relay-side NIPs, and you can check exactly which ones it can serve here:
https://nostrfy.org/docs/nips/If it also implemented verification commands like nak does, it could even replace nak, which would show just how powerful nostrfy is.