How much power is needed to run these speakers?
The maximum you need is an amplifier designed to drive an 8 ohm load with 120 watts continuous and 150 watts peak.

The load on the amplifier will be 8 ohms, given two 16 ohm speakers in parallel.

How much power you actually need depends on the space you are trying to fill with sound.  In a large hall, 120W may be appropriate.  In a small room, it will be deafening.  Comfortable listening in a small room may be only a few hundred milliwatts.