No, I have not heard of these. I have had Walla Walla (Washington State) Sweets, Vidalia Sweets from Georgia, and I forgot their name but from Texas sweet onions. But Candy Apple does bring up some taste memories and curiosity for sure!
From what area do they grow, and from what region do they sell them?
I see you are on the East Coast time zone area, I am out west. I perhaps may not be able to purchase them on the West coast. For shipping goods, the normal delineation line is the Rockies.