Adding speakers advice and help

I’d like to add a pair of speakers to my system. What I’m looking at adding is either the Martin Logan Motion AFX Dolby Atmos speakers to my Motion 40’s or add a pair of heights that’ll match my current speakers. This all is in a room which is about 16’x16’.

Any help with this choice is greatly appreciated and I’m open to all suggestions. I’m not sure if any other brand will match what I already have so help with that choice is also appreciated.

Thanks in advance.