Manual 40mm lens that covers the whole sensor?

Hey! So I've been looking at getting a 40mm focal length for my GFX but it's been tricky to find out if the lenses cover the full sensor. At the moment I've rocking the Minolta MD adapter and a 50mm 1.7 and I love the combo but was looking for something slightly wider.

So far I've discovered that the Voigltander Nokton 1.2 M mount covers it. I still wonder if the 1.4 version covers it as well as it is much cheaper. I was wondering if the Leica Summicron 40 f2 also covers the full sensor? As that lens is lovely.

Do you guys have any other lens recommendations? Looking generally for a 40mm f2 minimum. Other mounts brands? Just don't want Pentax or Nikon as I hate reverse focusing.

Also I'll be going to Tokyo in March, should I buy it there? And where?