I am using hass.io (Home Assistant) on a Pi3. Everything is LAN-only with SSL certs and all.. If you want WAN, you can decide on if you should/should not install certain plugins or buy certain products.
I have just started using HA, so I'm no expert. There has been a learning curve but it has "clicked" now and I'm starting to pick up on "what's going on". I looked into and tried a few of the other options but HA seems to be the go-to and it's easy to see why. That being said.. the interface "look and feel" is kinda lacking IMO.. but they are working on that with "Lovelace".. a new UI that is in beta... but I haven't got that far yet.
Check out
BRUH Automation if you haven't already!
I refuse to have a "voice assistant speaker" like Alexa, Google, etc. I haven't used it yet, but apparently there is a built-in and local voice option to HA so I might check into that.
I am using some cheap
ESP8266 D1 Mini's for pixel control for some of my "Pixels" around the house. They are running
ESPixelstick.... which integrates as a light in HA.
Tasmota for ESP8266 devices/Sonoff is a popular choice for other operations, as well.
Otherwise I have a HUE bridge with 12 color bulbs, 4 dimmer switches and 2 motion sensors.
2 LIFX bulbs.
1 WEMO switch and 1WEMO dimmer.
2 custom RGB pixel controllers; fishtank backlight and Christmas Tree (Obviously seasonal). Adding more, too.
I run 3 Ubiquiti AP's and a UniFi Gateway on a UniFi 24 port Switch.
Happy to answer any Q's as best I can.