communication with Portable unit

hi

for my new project i need to communicate between main unit and two portable handheld and one android phone. communication must be wireless and send and receive data command and voice (like walkie talkie). so i need help to choose a good and cheep solution.

some of project features:

main unit: uno 3 + WIFI or bluetooth (to communicate with android phone)+relay board+ditance sensor+?
portable handheld: nano + keypad + battery + LCD + ?
main unit and two handhelds distance: 100m
main unit and android phone: 15m
data type: command and voice
communication interface??? wifi or RF or …
handheld is like a combination of remote control and walkie talkie.

i have esp8266 yet didnt try it.is it possible to send data and voice with it? or choose NRF24L01+PA+LNA or Zigbee. im a bit confused.