[Sonnie]

Hello Rex and welcome to the Shack!

Sure, you can use centers for surrounds. The power really won't be an issue. However, I would probably mount the centers horizontally and not vertically.

I use a pair of Martin Logan Fresco's mounted horizontally for my surrounds. These are speakers which ML recommends for center and surrounds. They actually show them in a configuration mounted horizontally and vertically, but I am of the opinion that they will produce better horizontal dispersion for surround mounted horizontally and would be too direct if mounted vertically.