Dual Band Wireless 7260AC or 7260AN - What are the differences?

I'm buying a new laptop and I have the option of getting the 7260AC card or the 7260AN card. My primary network is 802.11N, but I want to be ready for AC since I might upgrade it. Is the AC one backwards compatible with G and N? Does the AN one not work with AC? Both are listed at the same price, which confuses me more. Both have Bluetooth 4.0.

Thanks,

P