I just went through this exercise and thought about a Karsten style piece. My problem is that I am left handed and most others who shoot my rifle will be right. Therefore, the karsten kind of doesn't work. I decided a amidexterous style is best and made my own. I used some PVC pipe, the kind that is used under sinks. It is thinner and smaller in diameter. I cut one side down the middle and used my torch to heat it up and basically flatten the sides. The curved piece fits my cheek and the sides match up with the top of the stock and down about 1 inch. I used high density foam with sticky tape to fill up the gap under the cheek piece. This essentially hold the cheek piece in place to the height I need it to be. I then just run a piece of electrical tape over the front and rear of the cheek piece and around the stock. The whole thing is then covered by a neoprene boot from sportsmans warehouse. It looks fine, functions perfectly, and cost me a total of $13.00.
The other option that I think would work even better is to simply use a piece of wood, shaved and formed correctly, with a couple of mounting studs that go into the top of the butt stock. Then you cover that with a removable cover for cleaning. No tape, just roll the cover forward, remove the riser, clean, replace. The only thing I don't know about is if the butt is hollow or not. Hollow butt might allow the riser to be quite stable enough.
Just a thought.