Asobinet made this accurate size, specs and performance comparison between the Nikon Z8 and Sony A7rV. I google translated the text and the specs that are the best ar embarked in red by Asobinet:
Sony A7rV store links:
In US at BHphoto , Amazon , Adorama , FocusCamera , BeachCamera , Buydig .
In EU at Fotokoch , Amazon EU , FotoErhardt , Calumet DE , WexUK . ParkCameras UK .
In Australia at CameraPro , Camerahouse , Sony .