Are you planning on curtains? I am new to houzz and I definitely don't have professional advice, but with the bed where it is I would think smaller nightstands would look better. It would also make the curtains easier to open and close if you have them.

On another note, I know this sounds crazy and no one would agree probably, but I don't always like everything centered and I love to use every inch of space and if it were my room I would probably move the bed over to the edge of one of the windows with a nightstand in front of the window, and on the other side put another nightstand in front of the wall and use the space by the window for something else. Maybe a small chair in front of the window. Or if there is room a small desk or storage shelf on that wall by the window. I hope that makes sense. It really just depends on what you need and want for the bedroom.