Nothing really, as for the ESP, I'm using a NodeMCU 1.0 dev kit, but that's just for convenience of uploading the sketch. All you really need is the display, ESP-12E and power.
And of course, you need something to host the VNC server at the correct screen size, in this case it's a Raspberry Pi.
And of course, you need something to host the VNC server at the correct screen size, in this case it's a Raspberry Pi.