If you buy one stone, make it a 1000 grit: it sharpens a dull edge and is fine enough to leave a keen, kitchen-ready finish. A 400 grit handles chips and heavy reprofiling, and a 3000 or higher refines toward a polished edge once you are comfortable.
The community compares brands endlessly (Shapton Kuromaku, Glass, and Naniwa Chosera all have fans), and the videos below show those head to heads. The honest takeaway is that a flat, well-used 1000 from any reputable maker beats a fancier stone used carelessly.
Our K&S take, naming only what we stock right now: anchor on the Naniwa Chosera 1000, or buy the convenience of a Chosera 1000/3000/5000 or 400/1000/3000 bundle, and add an Atoma diamond plate to keep them flat. We do not currently stock the Shapton 1000, so we will not point you at one we cannot ship.
