go with his SLD, it's worth it. I own a 240mm kuroshu gyuto and it's shocking how thin he gets them behind the edge and at the tip. they also act more like a stainless knife than a carbon steel knife.
I have a b1 240 custom handle as well, in SLD a few little ones.
Other sources for masashi in europe are dictum (sld), lorenzi (SLD), couteau japon (White stainless clad), niwaki (sld) insane prices, clean-cut but very few in stock.
If you need links let me know