Max Msp/Arduino - amplitude stereo control brightness movement of Neopixels

Hey,
I'm working on an installation that uses the amplitude of a stereo audio file to control 2 rings of warm white LED pixels (approx 280 pixels total). I'm a novice at both Max and Arduino so any help would be greatly appreciated. I've gotten Max to send Serial numbers to Arduino fairly easily using the following tutorial (https://www.youtube.com/watch?v=68L-WHh3Ows) and separately I have a rough Arduino Sketch (modified the strand test example) that just loops the Neopixels from full brightness to full darkness that I've been using to test some enclosures. Most of the examples I've come across deal with color and as I'm just using warm white Dotstar Neopixels these are not as helpful for my application. I trying to figure out how to do the following :

- Read amplitude of Left and Right channels from a stereo audio file in Max separately and send this information to Arduino as two different sets of numbers via serial. There is a lot of spatialization in the audio and I would like to map the two channels (left, right) to different areas of the Neopixel strips to reiterate the movement of the audio with light. The Neopixels will be in a circle around the user so the pixels to their left will represent the volume of the left audio channel and vice versa.

- On the Arduino side receive the two sets of numbers (originally coming from the amplitude of the stereo audio file playing in Max) and map the left and right to specific sets of Neopixels on the strip.

If anyone has any tips or knows of any examples dealing with amplitude and pixel brightness particularly regarding sending the volume information of the stereo channels in Max separately to Arduino via serial that'd be super helpful. Thanks for reading! Cheers, Koen