I did pretty much what you're looking for with about $900 worth of gear from Buffalo Tech. That was a year ago, so prices may vary.

I used two each of:
WLA2-G54L Router/Bridge
WLE-HG-DYG Directional Antenna
P/N unknown: Power over Ethernet to match G54L router
WLE-CC5:5m Cable

The antennas were the most expensive parts (yeah I could have built a pringle can yadda yadda - no time for that).

I have the bridges installed up in the rafters, and use their shortest cable (5m?) to the antenna (less signal loss with a shorter wire). The Power Over Ethernet modules meant I didn't have to wire AC way up there. I used two towers from Radio Shack. They've been in service about 15 months and I've only had to reboot a bridge twice. Encrypted transmission between the two bridges. I get approximately 100 MB/Minute of throughput. We use the link for VOIP (5 channels of a proprietary Panasonic system), plus all the regular data uses - file sharing, DHCP, printing etcetera.

My two antennae are about 1/4 mile from eachother with a 80% clear line of sight (one maple tree during summer).

The html interface on the routers was pretty straightforward.

-Zeke