I had a rather large Point to Point network at my former Job. It was using Ubiquiti Gear. It was for a Town Government I worked at, I had the main unit on top of the Town Hall->Went to a Cell Tower-> From there went to multiple water tanks and then to a few different buildings. only two or three buildings actually used it (like a very remote waste water building) for most it was just backup to the 1GB fiber. It worked great when it worked, which was most of the time. but Be warned, they take a beating from the weather to about every 2yrs you will be replacing them - which isn't cheap. Also make sure you get your wavelenghts right - with the point to point you have to mount one horizontal/vertical for certain wavelengths. I used Aurba for indoor APs but for outdoor point-2-point I didn't really like them.
Also you will want to do a site scan for nearby wireless at both locations (and maybe in between) make sure no one is one a channel to use and both locations. You should alos invest in some Ubiquiti Aerial cable it holds up better than just using Direct Barrier cable like most people do - it dries out in the air and degrades.