Is there any documentation on how to do this, I've always wanted to try the voice related ones but there is no documentation to run them outside of the haos setup

Basically you need to run this docker compose file from below and enable "Wyoming" integration in HA (I think it'll detect piper & whisper and propose it automatically). Don't worry about picking model too much - you can change it later in HA UI.

  version: "3"
  services:
  ## wyoming
    whisper:
      container_name: whisper
      image: rhasspy/wyoming-whisper
      command: --model base-int8 --language en
      volumes:
        - ./whisper-data:/data
      environment:
        - TZ=Europe/Brussels
      restart: unless-stopped
      ports:
        - 10300:10300

    piper:
      container_name: piper
      image: rhasspy/wyoming-piper
      command: --voice fr-siwis-medium
      volumes:
        - ./piper-data:/data
      environment:
        - TZ=Europe/Brussels
      restart: unless-stopped
      ports:
        - 10200:10200