Wireless NIC for Laptop

[minimoto]

I'm planning to get a new Mini-PCIe card to achieve higher speeds, but I have some questions.
1) What are the requirements for matching a NIC to a motherboard? (Just interface?)
2) Since my laptop originally wasn't dual band, can I install a dual band NIC it use it just fine or do I need a 3rd antenna?

I was thinking about using an Intel Centrino Advanced-N + WiMax 6250 http://www.ebay.com/itm/INTEL-CENTR...US_Internal_Network_Cards&hash=item1c251135af

Laptop:
Lenovo IdeaPad Z575 (A6-APU)

 

[miimario221]

instead of a PCI Express use a USB adapter. There more efficient and have faster processing.
Good Luck!