The flat Donut Peach, is all the rage for children to eat. Relatively small size, and easy for children to handle. Sometimes they are called UFO or Saturn peaches. I think UFO is a trade name.
They are no more difficult to grow than any other Peach or Nectarine. Ours are grown in large pots and kept over winter in the greenhouse and then all fear of frosts has gone, they are put ouside.
You must cover them or put inside during the winter, until the flowers appear (normally beginning of March). This is to stop the rain drops from dropping peach leaf spores onto the buds. The spores create gnarled looking leaves that can ultimatly drop off. Or if heavily infested the whole tree can die.
But its worth the extra effort, as the taste of a fresh peach, is amazing when compared to an imported on from the supermarket.