Speaker Improvement
The Polks are far better than the old speakers you have prior to your "downsizing" so your new "reduced" system should sound much better than the original. Unfortunately, the most common failing in the audio world is that of paying far too much attention to electronics, wires, etc. at the expense of buying decent speakers. It's always been true and your old system is a perfect example. The Polks are far better speakers than average old floor standing speakers like your old ones so whatever electronics you use, it'll certainly sound better because the improvement in speakers overwhelms any possible reduction in performance of the electronics driving them.