You don't mention if you have the wireless devices already?
If not, then for a simple, direct solution, I'd be looking at the
Ubiquity Nanostations 2.4 or 5Ghz.
http://ubnt.com/products/ns2.php
http://www.wlanparts.com/product/NS5...0211a_AAP.html
You could buy a consumer grade wireless AP/Client then an antenna and
maybe pigtail and mounting box or long expensive antenna coax.
Anyway you add it up, it would cost more. This is a pro solution
that should work out of the box. The built in antenna should do fine
for your distance.
Might have to buy the optional wall mount to get the angle
adjustment. Or cannibalize some discarded sat dish arms.
Steve