In-Wall Speakers

For a better sounding system, you'll want better sounding speakers. That may or may not mean buying Polk for your front speakers. Preferring one set up over another amounts to personal preference, and no one knows yours better than you.

That said, the rear speakers usually don't account for much in the home theater experience. So I wouldn't be too concerned with matching the rest of your speakers up with those Polks. But again, you may have a preference for the sound of Polk speakers. It's up to you.