>How many medium supers per hive would you suggest for maximum yield if using a single brood chamber.
A REALLY good year you might need five supers per hive. A bad year you won't need any.
>Also are queen excluders really necessary?
My guess is with a single brood chamber, you might want an excluder. I use all mediums for everything, brood and supers, and I do not use an excluder. When I ran two deeps I also didn't use an excluder, but the queen is not going to stay in one deep. She will lay in the supers under those conditions almost every time.