No experience with the Y start brand. I would go with a 1000/4000. The stones with lower numbers than that not only leave a lot of scratches, but in waterstones I have found that they wear and cup faster. You might take a look at some of the kitchen knife supply places just to see the wide range of products and prices. “King” is a relatively inexpensive but decent Japanese brand. Also, be prepared to flatten your stones after they begin to show wear, using anything from sandpaper on a flat surface to a diamond stone.