If you run gasoline or coleman fuel, you will get a lot more mileage out of each ounce of fuel. But.. the needle valve will be harder to set.
If you use a 2 ounce tank for gasoline, (or coleman fuel) it will be enough to fly the OTS pattern. If you find that you don't like gasoline and you go to glow fuel, the 2 ounce tank will not be big enough to fly the OTS pattern. Then you need to put in a larger fuel tank.