My KEF R200C is perfectly matched to my KEF R500 main L-R speakers, sonically and cosmetically.
KEF does this with the R, Q and C lines of speakers, as do almost all major makes. I can't imagine any quality maker of loudspeaker systems wouldn't put the same level of matching into theirs. Can you point out any specific examples of a series which DOESN'T reasonably match them on all levels?