[HardDrive]

This is very poor idea for many reasons, not the least of which being that the vent will be totally ineffective because its too far off the cooking surface. Regardless of the material used on the curved section, it will be constantly coated with cooking grease and difficult to clean. Tile would be a nightmare.

We had a similar situation in our kitchen. I built a soffit that ran the entire length of the wall on that end of the room, and hid the ducting in the soffit. Our friends in Seattle (by chance we are flying there tomorrow) had the same issue, and elected to have nice a nice stainless shroud that covers the ducting fabricated. It looks great. I'll snap a photo tomorrow night if you like.