+1 on suggestions to use one good amp and bi-wire the speakers. However…
Few things to consider here -
1. The ML panels present more challenges to the amplifier than the woofers do. This is because the impedance on the panels can dip below 2ohms. I do not think your rotel is a good match for these speakers and bi-wiring is unlikely to improve things much.
2. When you say your woofers distort, what kind of distortion are you talking about? What does it sound like? Could have nothing to do with amplifier and bi-wiring is unlikely to resolve it.