I would recommend getting a stone with a lower grit (less than 800) after you get a polishing stone, as the main uses of a lower grit stone would be to take off a lot of metal very quickly (removing chips). Its better to get a bit of experience on something a bit slower (1000 grit) and learn to hold a steady angle before diving deep into lower grits. The only time I could have used a stone lower than 800 grit (I used a 500 grit) was when I was completely changing the edge on a Kasumi (59-60HRC) knife.

Just FYI; This is the #1 problem I see with most brand new kitchen knives. A blade that gets thick quickly past the cutting edge may shave hair and still be unable to produce clean cuts on food items because the thick area acts as a wedge and starts to either bind the blade or split the food like firewood rather than cutting cleanly all the way through.