I personally purchased Shapton kuromaku stones, 1k,2k,5k,8k and a used 12k naniwa.
Bought all stones from Amazon and they are for the money awesome stones. Really affordable, after doing some reading and looking this about the best deal I could find getting all the same brand. I like the speed at which they work and the finish produced. These are the Japanese version of the Shapton pros IIRC. Great suggestions so far from these members.