I think you've gotten some good advice here. A 3000-grit stone will make
sharpening quicker, and you won't dish out your finishing stone as quickly
because you won't need to use it as much.

You might find that the finish put on by a 3000-grit stone is quite good, better
than you might expect.

Don't get too hung up on brands. I've got Sigma 1000-grit, Naniwa 3000-grit, and
Shapton (whatever high number that one is)-grit stones. They all do the same
thing: sharpen tools.