I was recommended this brand of wireless card about a year ago. Compatible with Windows/Linux/UNIX, this is the type of card you would use for rigorous wifi analyzing or wardriving.

Ubiquiti Wireless Card SR71C 802.11N/G/B/A w/ 2 Antenna Jacks & Clip-on Antennas

http://www.data-alliance.net/-strse-137/Ubiquiti-SR71C-SR71-dsh-C-MIMO/Detail.bok

Ubiquiti SR71X Wireless-N Card for Express Card Slot. Has Antenna Jack. 802.11N/G/B/A

http://www.data-alliance.net/-strse-104/Ubiquiti-SR71X-300mW-802.11N/Detail.bok

You can find more products on their website (http://www.data-alliance.net). They also sell these on eBay. Just search Ubiquiti.