If you're smart, you don't.
The things are a bitch to clean if made of stainless steel. Stone means you won't get to use some of the more effective cleaning chemicals. It also means a more porous surface, unless we're talking surface-plate-level polished granite...
Stainless hoods are hard enough to keep really clean. Are you sure you want to get something even worse?
If looks are what you're concerned about, get a stainless steel hood covered with whatever material. The folks remodelling the rest of your kitchen should be able to help you out...