power is not single number as you are covering at least 2 if not 3 or 4 bands of energy
the power needs for the low end are significantly larger than those for the other three bands
what I would need to know is
venue capacity
venue dimensions (HxWxL)
any strange sections in the venue i.e. angled walls, smaller depressions in the walls - these affect frequency response and therefore require additional measure to compensate and cover correctly
planned speaker use i.e. sub-bins, mid bins, high freq bins etc, passive or active crossovers? etc