conexion a la pc con un arduino uno r3

hi all I have a module r3 arduno one and want to connect it to my pc .. to lower the converter I can use the chip ATmega8U2 version, I was using the Atmega 16U2 but not to release this version in the page that tells me the only arduino 8U2 .. I can give the link of the 16u2 or download the 8u2?

me pueden ayudar con el codigo xbee del receptor y transmisor por favor ?