Im not sure how those cards connect up, but for an antenna, a bi-quad on an old small satellite dish will give you about 24 - 31 dbi, which should be plenty and is simple to build. Im very happy with my non dish biquad.
Analysis of the biquad here : http://www.lecad.uni-lj.si/~leon/other/wlan/biquad/
For feeding a dish, you want to stick to the basic biquad, not the double biquad.
The biggest losses you face with wifi is the antenna coax cable, which can be horrific. The cable must be kept very short, about a couple of meters max.
2 x UFL Ultra-miniature coaxial connectors
This sounds very bad. Skinny coax has the highest losses.
Another option is to scrap those wifi cards and put a USB wifi adapter at the focal point of a dish. Then you can use slightly longer USB cabling.
WiFi distance record: 237 miles : http://www.engadget.com/2007/06/19/v...ord-237-miles/