Hi,
I'm known with both Minidsp and hypex Fusion amps for some reasons I would go for a Hypex Fusion solution as this will be more easy to wire I suggest a 253 or 503 unit for 3 channel amplification (high, mid high, mid bass) and 1 unit for the woofer(bass) for example if your source can do AES as source you can daisy chain the Fusion amps and skip the ADC. If you go for Minidsp you have al lot of external wiring that can make it more open to issues and possible distortion.
I currently have Minidsp but I have the AudioPraise through the minidsp 88D/BM to the Okto research dac and all balanced out to my amps and then speaker wires. Looking back the fusion amps from the 88D was an option but meant I had double dsp and directly into the fusion from the Audriopraise I would not have Dirac.
Hope it helps,