Lightning / surge protection on a branch circuit has much less requirements than at a 'service entrance'. This is because of the impedance (read inductance) is greater and slows the rising edge of the lightning waveform so the peaks are less. ( In the USA UL has done quite a bit of research, studies, and testing and has standard waveforms shape, peak voltages.). The best protection after the fuse is a common mode choke with 2 or 3 MOVs and /spark gaps on the input and X and Y caps on the output.