This is a possible option if digital input is needed, but a few changes can be made.
First, the TAS3251 can output 175W into 3 Ohms in BTL mode so no need for two devices in PBTL. Just make sure they do decent thermal designing.
Second, if a pad down device is necessary, then theTAS5827could be used which can do 55W output into two 4 ohm speakers (10%THD), but thermals will be trickier to manage due to pad down nature. Because the customer is already using a heatsink for the TAS3251, I would recommend theTAS5828M which can do the 2x50W no problem since it uses a heat sink.
