We have no chance to give you a good suggestion with so little data of your project. You don't tell us what you want to do with that project and you write nothing about limitations (technical, financial) you have.
Is it possible to add a rfid and a wifi shield together?
It's possible but depends on what hardware you'll be using.
Hi David:
I think 433MHz radio data solution is suitable for your application. Does the device have standard UART interface? If yes , most similar solution fulfills the requirement. Need i recommend one for you ?