Mid level b&w speakers would be best. The finer models might reveal weaknesses and compel you to get a classe
LOL! B&W 600 series to CM series are fine with Rotels, while the PM1, 700 and 800 series are best delegated to Classe
meanwhile..
The Rotels are quite bright, pair them up with a warm / balanced / dark sounding speaker pair and that should even things out.
Other speakers marques to consider and its general sonic characteristic
GoldenenEar (Balanced) , KEF (warm), Mordaunt-Short (Warm to Balanced), Focal (Balanced), Monitor Audio BX series (warm), Dynaudio (warm), Wharfedale Diamonds (dark), Mission MX (balanced), Acoustic Energy (balanced to warm)