It is a good idea to buy a USB-TTL adapter instead of using an Arduino Uno.
For the ESP8266, I particularly like the adapters that use the CP2102 chip because it is 3.3V on its TX and RX pins such as this one sold on eBay Cp2102 USB 2.0 to UART TTL 6pin Module Serial Converter Adapter Blue Silver N3 for sale online | eBay