My node in the city is running a D-Link 900ap+ inside a weatherproof case.
1 meter Reverse SMA - N connector attached to a Borg 8Slot Waveguide.
For power, I use Power over ethernet through about 50 metres of cat5.
This is fed 12 volts by an ATX power supply.
At the weatherproof case end, I get the power (now 11.5Volts) and regulate it down to 5volts (actually 5.1) before feeding it into the AP.

The regulator circuit is capable of regulating up to 1.5Amps. I also use an old cpu heat sink to disspate the heat from the regulator. This is mounted in such a way that the heatsink is outside, but sealed and the regulator is bolted directly to it, but inside.

Cheers
John