The latest firmware should be used with the latest version of the ESP firmware, available here - https://github.com/subpos/esp_firmware_v2
You can order 3 of these boards for $7.5 including shipping from OSHPark here - https://oshpark.com/shared_projects/0TVEe4yb
Note, the current Node design will not support Time of Flight. Because of this, there is no need to populate QG1 as the firmware just uses the internal PIC oscillator.