Can you not connect the CTs to where the cable from the power meter box enters the property and meets the distribution box?
If not, I’d use a Pi ZeroW, PiJuice UPS hat and an EmonTX. Connect the PiZero via the serial/UART to the EmonTX.
TBH, I have not suffered any SD Card issues due to power outage. I believe that any associated power spikes are the cause of corrupt SD Cards - all my Pis are behind surge protectors.