OK
Guys, i can only talk in my experience as a prof wi-fi integrator, so here i go.
If you need to reach far away regions u need to have a look at Ubiquiti stuff.
If your talking about 1000M and plus i'd advice you to have a look at the nanobridge M5 solution.
http://ubnt.com/nanobridge
They go about 60$ each .. so you'd have 120$
As for an iP cam i'm sure the rest of the guys here can help you out. (i'd opt for Axis).
For permanent powering you can have a look at solar pane (1,5m * 60 cm) will do the trick.