EMS Madara>EMS Sasuke, so I'm just gonna assume that MS Madara>MS Sasuke, not to mention his chakra>Sasuke or Itachi's. He wins both scenarios.
True he has more powerful chakra and base arsenal than Sasuke but wouldn't they both undergo MS strain at the same or similar rate? Susanoos stalemate each other but Sasuke can use Kirin then follow up with Susanoo slashes to destroy Madara's Susanoo and kill him.
Summonings gives Sasuke the win. Itachi gets raped.