Jon Broida of Japanese Knife Imports has this to say about the Naniwa Akamon 1000 in his blog:
"For a long time, we have carried the Naniwa Akamon 1000 grit stone as our Large size stone. Besides being a good stone, I have sentimental attachment to this stone as the first stone I really learned sharpening on (it was a gift from my chef in Japan). However, since developing the Gesshin line of stones, I find myself constantly testing new stones and new formulas. One day, a little while back, I found myself testing what would become our new Gesshin 1000 Grit Extra Large stone. Initially, I was really impressed with the cutting speed and tactile feedback of the stone. It also resisted dishing pretty well. It was a much faster cutter than the Naniwa and had equal if not better tactile feedback."
Might I suggest you give him a call, and talk with him about your sharpening needs, and what he recommends, rather than trying to find specific stones that may or may not meet your requirements. He's really easy to talk to.
The number for JKI is (310) 399-0300.
Rick
