Project on wireless light control system.

Hi guy i will like to ask for advice before purchasing the item.

Main (master)
1 x arduino uno + 1 x arduino wifi shield + Xbee module (unsure which model to purchase)

slave ( slave transmitter)
1 x arduino uno + photo sensor +xbee module ( to send back to the main master board, transmit photo sensor data back )

slave ( slave receiver )
1 x arduino uno + LED panel + xbee module (received photo sensor data from the main board and adjusting the light brightness )

i will like to ask which transmitter/receiver can compatible with the wifi shield?
thanks you.