I have an ARIMA(4,0,2) model that works well for 168-differenced data, that is, I fitted it to $Y_t-Y_{t-168}$.
Based on this, would it be a good idea to try to fit a Seasonal ARIMA(4,0,2)(0,1,0)[168] or a SARIMA(4,0,2)(0,1,1)[168]?
What would be a good way to decide the order of the polynomial in $B^{168}$ in front of the white noise terms?