Price wise I can get the Polk new for 113 each, the cs80 second hand for $50 for two.
Not quite sure on specs, and weather worth paying extra for new but smaller speaker
(To either go in wall as rears, or ceiling for Atmos)
Those are some pretty old, Chinese made Paradigm's...
Do the Polk's have magnetic grills? If so, they're probably the pick.
However, why / how limit yourself to these two options?
Paradigm had multiple levels of speakers in that era (well, they still do), the ones they chose to manufacture in China were lower spec'd units.
Their Canadian made speakers cost considerably more and did sound vastly better.