I will not repeat the good information already shared. I will tell you what I have and use in my little shop of horrors. I have a 250 grit King stone to remove heavy metal. I then jump to a 600 grit, 800 grit, 1000 grit, 1200 grit, 4000 grit and finally an 8000 grit stone. These are all water stones so there is no oil mess to deal with at the end. Now, there are stones that go much higher than 8000 grit, but at this height you are pretty much washing out the use of green rouge for stropping.
I recently started switching out my King water stones for DMT Diamond stones. The best benefit that I found has been that I do not need to pre-soak the stone or re-level them when they cup after repeated use.
I have also purchased a 1"x30" belt sander. I found a US supplier for AO belts ranging from 80 grit up to 1200 grit and a leather stropping belt. The same company has available an attachment that can lock in angles for certain sharpening of specific tools. I have tried this setup on my older dull kitchen knives (don't tell the wife) and it has work out better than expected. I have cut my fingers more then once in the kitchen by just touching the blade.
Finally, I have not had much luck with any type of files. With my "V" groover (hand tool adjustable?), I sharpen it by hand to include my "U" groover. You just have to do it carefully at a higher grit to prevent ruining the angle.
Just food for thought. Take everything you read here and play with what you have and learn. Good luck and Happy New Year!