I already have a audio pro c10 and could buy another to make a stereo pair or try something new like the q acoustics m20
Welcome!
Re your Audio Pro, I’m not sure that you can make two of them into a stereo pair. At least not in the manual I’ve read. Did you check that option for sure?
In any case the Q Acoustics are designed as a stereo pair, so would be my preference as long as they offer the connections you needed.