If you want to brew it yourself, try these two
http://www.fab-corp.com/
http://www.demarctech.com/

If you want a boxed solution, Cisco, Alcatel, and others sell 5.8GHz solutions that are either 802.11a compatable, or proprietary. There is also Motorola's canopy gear. WiMax based stuff is probably also worth googling for.

a 200' tower at 7 miles from each end point of the link is probably the MAX you should need.