Dokuwiki (dokuwiki.org) is my usual go-to. It’s really simple and stores entries in markdown files so you can get at them as plain text files in a pinch. Here’s a life lesson: don’t host your documentation in the machine you’re going to be breaking! Learned that the hard way once or twice.

For reverse proxies, I’m a fan of HAProxy. It uses pretty straightforward config files and is incredibly robust.

I can’t give direct experience here, but this is exactly the use case I’ve been meaning to spin up mailpiler for: https://www.mailpiler.org/. One of these days that will rise to the top of the priority list.

This promises to be a fun project!

It sounds to me like you have above-average demands on your network and I’d agree that UniFi (and therefore probably Omada) are not what I’d consider great as routers/firewalls.

I’m a fan of pfSense/OPNSense for that purpose, which you can install on pretty much any x86_64 hardware. They’re both wonderful and you can fine tune to your heart’s content or get them set the way you like and leave them.

If you really like a dedicated router appliance, I do like the Mikrotiks, too, but you’d have to study their sometimes-peculiar way of doing things.

To my tastes, UniFi does great at switching and wireless, but any of you’re unhappy with that direction, I’ve heard good things about Omada and the Aruba stuff is fantastic. I recently have been playing with some used iap-325s from eBay. I picked them up for $25 and they’ve been terrific.