Would be helpful if you outlined exact make and model of Speakers.
I am only guessing at what I find on google, that you have 4 Polk RM1300, then a pair of Q Acoustic M20.
I don't get much back on the C510 you show as your Center.
Your biggest impact in Sound Quality will come from your Front 3. You don't have to match them, though it help if they sound more alike than not...
Let us know what you are actually using rather than guessing, please.
How much are you willing to spend on this?