WiFi commercial applcation- need help

I need help in researching a strong WiFi rounter for a two story building. I need a Hi gain solution. Can anyone point me to a product or website that has something better that the $200 Cisco/Linsys models at BestBuy?
I need a single point solution as opposed to deploying multiple WiFi routers or repeaters thru the building.
Thanks for any advice. Alex