I am not sure that any magnification is necessary. American Rifleman tested the Storm rifle, and the best group they could get at 25 yards was 2 inches. that is more than 8 MOA.
For the most effective aim, use one of the inexpensive Holo sights, for better target acquisition. To me shooting it with both eyes open would be a priority.
Enjoy it, they had a lot of good things to say about it.