If you want pieces large enough for one piece scales, I think you'll have to go with Red Abalone. Those shells can go up to 11 inches in diameter and are very thick and require a lot of grinding (respirators are a MUST). I'm going to be making some one piece abalone scales but it's a bit of a challenge. For a 6/8 razor, you need 5.5" of abalone that's flat and thick enough for scales. Even with large shells, there aren't many pieces of the shell that would work for that.

You won't find pieces of Paua abalone large enough to make one-piece scales. The shells are rather small and thin. They're beautiful but only good for inlay and mosaic work. Abalam is the only option for one piece scales with Paua abalone.