Assuming you'll keep the Polk loudspeakers, then keep the Denons. The Parasounds are good quality equipment, but it's not a big step up from the Denons in your system. I would have the Denons tested to make sure they are operating properly. They may need to be re-capped or cleaned.
Replacing mid-80s Denon amp and preamp with new Parasound equipment
I have a Denon PR-1000 preamp and POA-1500 power amp which I bought new a few decades ago. I am considering going with a Parasound P5 preamp and 2125 v.2 or 2250 v.2 power amp. I need two sets of speaker outputs (A/B) so I can't go with the Halo series amps. I am running a mid-80s set of Polk Audio SDA-SRS tower speakers. The Denon gear has served me well over the years but I am thinking I should notice some improvement with the Parasound. Would you agree?