Microcontroller and Zigbee interfaced chip

Hi
I want to interface a microcontroller and zigbee transceiver for home automation project.

When i browsed through atmel's website. I found the following models in which they are already interfaced and available in a chip format.

http://www.atmel.com/dyn/resources/p...ents/8266S.pdf
http://www.atmel.com/dyn/resources/p...ts/doc8226.pdf

The atmel's web page for the wireless chips is
http://www.atmel.com/products/zigbee...ource=main_nav

But i dont know what is the difference between these 2.

Which is better for my project?

The first one is cheaper than the second.

Also i would like to know if the chip itself contains the antenna in the above 2 cases or should we attach an antenna separately?

If there is some other better chip available for this kindly let me know.

Thanks..