Hello from our new/old house in Trent Woods, North Carolina.
Turns out that the house we purchased has (had actually) a very old automatic dishwasher that died today. So the wife and I headed to the big box store to pick out a new one. The sales guy happened to mention that NC updated there electrical code requirements within the last two years and that if my old one didn’t have a separate switch I’d  have to get one installed. Sure enough, when I pulled the old machine out I discovered it was hard wired into the same switch-box that the garbage disposer get its power from. This box is under the sink (kind of awkward for turning the GD on and off). In any case, there is no switch for killing the DW if it needs to be serviced. So I’m thinking I could add two switches in the backsplash; one for the GD and another one for the DW.
The question: Can one line be used to feed both machines via the two new switches? Also, do these need to be a GFI type? 

Thanks for any help you can provide.