Hi there ,
Suggest two RF module , it can directly connected to arduino some as Grove -RF .And the library you can find on the wiki page. Thanks.
http://www.seeedstudio.com/depot/315mhz-rf-link-kit-p-76.html?cPath=139_140
http://www.seeedstudio.com/depot/433mhz-rf-link-kit-p-127.html?cPath=139_140
Deray