Help picking an amp to work with my system

I recently obtained some Martin Logan ESL X speakers and absolutely love them.  That said, they are part of my surround sound system, so I use them for both, listening to music, and then when I want to do movies, they become the left and right channel of my surround sound.

I’m currently Bi-Amping them off of my Denon 4520ci receiver, but have had issues with them starting to distort if played at around 95db on a heavy bass song, within halfway through the song.  I posted about it in another group, but my post was deleted.  I believe the receiver I’m using just doesn’t have the capabilities RMS to keep up with that draw (Astronauts in the Ocean by Masked Wolf is a perfect example of a song that will sound crisp in the beginning and halfway through, start to distort).

I still need my receiver for surround functionalities, but for these two speakers, I was considering getting a dedicated 2channel amp and use the receiver as the pre-amp for them.  Does anyone have any recommendations on an Amp that’s affordable and clean?  I was thinking a Peachtree Nova 300, hopefully I can find one open boxed/used.  Would this unit fit my needs, or would it be pushing it with these speakers even using that amp?