I use a diamond stone combo for my knives. Currently, I use these two:
http://www.amazon.com/Smiths-DCS4-C...YV6L/ref=sr_1_3?ie=UTF8&qid=1327472770&sr=8-3
http://www.amazon.com/Smith-Abrasiv...IE/ref=sr_1_35?ie=UTF8&qid=1327472834&sr=8-35
The course side to the wand is 325 grit if you should ever need to reprofile an edge. The small stone (which gets the most action for me) is 400 grit, and it gives a nice hair poppin' edge to my knives. And, finally, the fine side of the wand is a 750 grit diamond stone, for if you REALLY want to put a pristine, razor-edge to your knives.
As said before, S30V takes to diamond sharpeners in an amazing way, and I agree 100%. It's all I use for my S30V and 14C28N knives. You really don't even need honing solution if you don't have it.
Again, the 400 grit stone is all you need if you're going to piece this together one stone at a time. If you maintain your blade regularly and don't go crazy (chip at concrete or metal with it), this should be all you need to keep an EDC blade razor sharp and ready for action. It will put a NICE edge to both kinds of steel, with very little work. I'd swear by that tiny stone if I had to.
It's size makes it difficult to sharpen larger knives, but it's easy to get past that since it does such an excellent job.
Alternatively, for larger knives, you can get this:
http://www.amazon.com/Smith-Abrasiv...6G/ref=sr_1_23?ie=UTF8&qid=1327472817&sr=8-23
I don't have this stone, but it appears to be a larger form of the wand. Same coarse (325) and fine (750) sides on a stand for two-handed sharpening.