hi sensitivity lower power with b&w

I heard more watts is better for b&w's. If i use lower power but higher sensitivity amps, is it equal to higher power lower sensitivity amps?
No, no...
You need Watts at the OUTPUT of the amp to drive the speakers.

Amp "sensitivity" has to do with how much input energy/volts is needed for the amp to reach full output. This is usually very low 1-2 v.
Watts: the amount of energy the amp outputs.

The amp, "multiplies" or offers "gain": i.e. you put in 1V and you get many more at the output.