Node MCU who provides the LUA firmware also propose evaluation boards: http://nodemcu.com/index_en.html#fr_54747661d775ef1a3600009e
An Arduino + ESP-01 board, with an ATMega 644: http://rayshobby.net/cart/esptoy
ATMega 644 has two hardware serial ports
ESP8266-EVB is Evaluation board for ESP8266 with relay, button, UEXT, all GPIOs available on 0.1“ header https://www.olimex.com/Products/Modules/Ethernet/ESP8266-EVB/open-source-hardware