I have quite a few tools for sharpening including washeta whetstones that come as a triangle shaped unit in coarse, medium and fine, Smith's ceramic sticks, a hard Arkansas stone from Garrett Wade tools. I have recently picked up a DMT whetstone in 'fine' grade for stainless blades. I am thinking of getting a Norton 4000/8000 for really fine work such as a couple of straight razors I have but have yet to use to any extent.
I also ordered a strop from the man above.
Now to the heart of the matter. I've heard of people using a cinder block who state it isn't the tool but the technique. For the halibut I've used the unglazed underside rim of a coffee cup because I read it works and it didn't do bad at all. I just tried it to see if it would without real experimentation.
In this specialized world there is a place for everything. These straight razor folks know quite a bit about sharpening:::
Hones