The HU and the amp get along rather nicely. My Camaro has the monsoon amp, I took the radio out, put an Alpine in and it's not complaining.
However, if your rear speakers are biamped, you will have a hard time with the new speakers. That's something worth looking into before ordering the speakers. There would be 2 clips showing in the trunk on each speaker.
2̶0̶0̶3̶ ̶P̶o̶n̶t̶i̶a̶c̶ ̶G̶r̶a̶n̶d̶ ̶A̶m̶
1994 Olds Cutlass Supreme
2̶0̶0̶2̶ ̶C̶h̶e̶v̶r̶o̶l̶e̶t̶ ̶C̶a̶m̶a̶r̶o̶
1996 Infiniti G20
1993 Chevrolet Lumina Z34
1989 Buick Regal Limited