Upgrading my sharpening system. Japanese combo stone grits?

So I've decided to invest a little money an improve my sharpening kit.

Right now I have a cheap big box store combo stone, falkniven DC3, and triangular pocket sharpener (for my serrated blade)

With this setup I can pop hairs off my arm with every knife I own, but want to get to the next level with that beautiful polished edge the higher grits seem to achieve.

I was wondering what kind of combo stone I should look at. As of the moment I've been looking at a 1000/4000 and a 1200/8000. I have around 100 bucks to spend and was thinking about one goods stone. The other option I was looking at was DMT's the diamond stone set, x-fine, fine and course. Just looking for some reccomendations.