Mary, welcome back! As John Bridgman suggests, unless the fireplace is going to take up nearly the entire width of that wall area, there should be enough room at the side for your speakers.

Although the separation might be narrower than ideal, the M60s or others in that position should certainly be better than a sound bar. Of course, they wouldn't be toed-in, but rather face straight ahead or maybe even experiment with some toe-out to get more spread and reflection from the side walls.

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Enjoy the music, not the equipment.