You didn’t say the size hood. IMO, a custom cabinetry hood only looks good when it’s at least 36” wide. Otherwise, its proportions look squished and heavy.
Contractors and cabinet sellers will almost always advise a cabinet surround, regardless of your kitchen size and design, since it adds to the cost of the kitchen, both labor and materials, and to their bottom line.
The problem with the 2 photos you posted as ”The two possibilities” is that one is sleek and modern, and the other is more mundane. Makes it seem like a stainless hood must be hohum compared to a cabinetry surround hood, and that’s all there is. There are many sleek stainless hood designs. They usually offer an optional duct cover that can be quite seamless, as an alternative to having the hood hang from the cabinetry. Easier to wipe down too.
Q
info about step up from 6" to 8" ducting
Q