Your acf plot is ambiguous. The paradigm you are trying to follow to identify the SARIMA model sometimes works when 
     1) there are no one-time pulses in the data
     2) there are no seasonal pulses in the data
     3) there are no level/step shifts in the data
     4) there are no local trends in the data
     5) the underlying (waiting to be discovered ) 
        model generates errors that have constant 
        variance
     6) the underlying model has constant 
        parameters over time.


If you post your data (which is always less ambiguous) , I will try and help further.