Sorry Paul (@fahrvergnuugen) - We/I’ve hijacked your thread a bit.
I guess you have looked at the IoTaWatt already?
The Adafruit WICED Feather looks interesting, but I think at $35 (and currently out of stock) I would perhaps spend less on a STM32 with more ADC’s and to that add a cheap esp8266 running emonESP and save a few quid whilst getting more channels as you would still need to add the monitoring front end for either option.