What speakers are better to use for left/right with a home theater projection screen?

Bookshelves speakers look alot better for a screen because you can positioned them right on the center of the left/right side of the screen but do Bookshelve speakers provide as much sound as floorstanding speakers. My choice for bookshelve is two of the new HTM61 from the new B&W 600 series or two 684 floorstanding speakers which are from the new 600 seried also