If you really want symmetry, you can get 2 mono blocks for the same price.
https://www.audiophonics.fr/en/power-amplifiers/audiophonics-ap300-m400et-power-amplifier-class-d-mono-purifi-1et400a-1x400w-4-ohm-p-18444.html
But as @Bob101 said, the power supply is what generates the most heat (not...