Well, most copper range hoods, like sinks, are going to be sealed against corrosion/tarnishing. It is wear and scrubbing that may ruin this over time. Then you would be looking at frequent polishing.
I would seriously consider an induction top or range in a small kitchen. A 36” gas range can be a blast furnace in a small space. Also, you will need less CFM to vent an induction top and this means that you will be able to get by with a quieter vent hood.
Our biggest mistake with our remodel was not arguing with a local building inspector who stated we need a high velocity fan for a 36” range without considering it was not gas. Now we have a F16 worthy fan in the kitchen.
