Check out this Nord amp. It is the exact same price in USD as the Hypex NC400 kit, but it comes with the NC500 module, an input buffer, a bigger power supply, and it's already assembled.
https://www.nordacoustics.co.uk/product-page/nord-one-nc500dmst-3
If you buy the stereo version, it's actually cheaper than two Hypex mono kits.
https://www.nordacoustics.co.uk/product-page/nord-one-nc500dmst-3
If you buy the stereo version, it's actually cheaper than two Hypex mono kits.