Re: wood or metal
Wood looks great on a narghile but it's not practical since all of it needs to be washed regularly. I know that rigs with wooden downstems are threaded so they can be thrown out after a few uses. Typically you buy a 5 or 10 pack of spare down stems when you get the rig. If that isn't an option I wouldn't buy anything with wood. Still, wood does look great.