You would probably get better responses if you post in the Wireless LAN FORUM »Wireless Networking.
That being said, I have seen devices similar to the UA600 used, but not for 1.5 mile range. Maybe 0.5 mile. The UA1000 or UA2000 »www.ampedwireless.com/products/ua2000.html would probably be your better choice. I do not know if it could get to 1.5 miles, but maybe 1.0 miles.
There is a company Ubiquiti »www.ubnt.com/ that has some good equipment. If you have lots of money you could try the AirFiber »www.ubnt.com/airfiber. For those on a smaller budget. You might need to use an AirGrid »www.ubnt.com/airmax#airgrid to get your signal.
There are people more familiar with the Ubiquiti equipment in the WLAN Form.