When your talking the same grit, like 8k, in the finishing range, it's personal preference. Thuringian, (which are normally a bit higher than 8k) Coticule, or Naniwa. Arkansas stones are in a class by themselves. They're not rated like most hones.

1k stones are for bevel setting, 4k are for sharpening, and 8k and above are your finishers. Shave ready blades can be maintained indefinitley with a bit of skill and a barber's hone, or something in the 10-12k range. I'm surprised Glen didn't link to his post. It should help you guys out a bit:

What hone(s), paste(s), or spray(s) do I need? - Straight Razor Place Wiki

I also don't recommend naturals to guys just learning how to hone. Stick with the synthetics. Your results, (when they come) will be more consistent.