Use two stereo ICs or four single-channel ones.
These look like a possibility:
There are schematics and PCB layouts in the data sheet:
If I were building one for serious listening, I'd use a Class AB amp such as that or discrete components, not a Class D one.
The Class D types are great for background music etc., but are generally not high quality - eg. that TDA7293 IC above is rated maximum 0.1% distortion at 50W.
The TDA7498 Class D 100W IC is also rated 0.1% - at just 1W and 10% by the time it reaches 80W...
(And many of the Class D IC are surface mount so difficult to use or heatsink, other than buying ready-built modules).
There are circuit boards to take the TDA7293 available cheaply on ebay, as well as ready built modules - but I'd not trust the AC input ones & I'd also rather be able to choose my own components so I know the quality..
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Get the ICs from a reputable electronics supplier rather than ebay.
You will need large! heatsinks and a well rated and well-smoothed power supply. Class AB amps are only around 50 - 60% efficient, so the heat dissipation will be near equal to the power to the speakers, and the load on the PSU the sub of both.