Start with two surfaces -- one medium/coarse for drawing the first burr and one medium/fine for drawing a fine burr, and doing a little polishing. The medium/coarse stone should be in the neighborhood of 1000# JIS, and the medium/fine stone should be somewhere between 4000# and 7000#.
My recommendation depends on how much you want to spend, what your skill level is, whether you want to keep the stones for awhile and so on. For the present, my generic recommendation is the Bester 1200 for medium/coarse; and either the Suehiro Rika 5000 or Takenoko 6000 for medium/fine, depending. Extrapolating from the very little I know about you, the Suehiro is probably a better choice. It's more beginner friendly, and cheaper too.
The idea behind starting with two surfaces is to learn to draw a burr, chase it, and deburr on the medium/coarse stone. Then, when you can actually improve an edge at that level, develop some consistency (and sharper, more durable edges) with the medium/fine.
Once you're consistent at holding the edge angles you want to hold, you can move on to a coarse stone for repair and proflling. You probably won't use the coarse stone more than a few times a year. If your knives can benefit, you might want to add a very fine polishing stone at the same time you buy the coarse.
Coarse stones have consequences, so you want to make very sure you're in control before using them; if you're not ready, you'll either spin your wheels to no effect or more likely round the edges over on an expensive polishing stone. No point in buying either or both until you can use them.