I need to connect over Wi-Fi two installation, let's say security cameras, around 350 meters apart, both outdoor at around 1500 m MSL with about 100 meters difference in altitude. Line of sight between the two is obstructed by trees (sparse). I was thinking of using CPE510 or CPE210. Both can be mounted at a maximum height of 2 meters from the ground, in both location. There is no cover for the weather from any direction in both location. Power usage has to be the lowest possible, the WiFi equipment might be turned on only for the required time. Price is also a factor of concern and shouldn't exceed 120€ total. The amount of data transferred between the two shouldn't exceed a dash of MB. 

Imagine a pole on a slightly sloping ground at the edge of a forest ( Main installation, with the device configured as AP), some sparse trees, a grass about the size of 1.5 football fields (long side perpendicular to the main installation) with a pole in the middle of the lower third (Second installation, with device configured as Client). The main installation is the one at the highest altitude.

What I'm asking is if CPE510 or CPE210 are a good choice, which one is better? Could an high gain (13dBi) omnidirectional antenna in the main installation connect to a high gain directional antenna (15dBi) on the second installation do a better job? For the second option, the omnidirectional antenna is transmitting in the 2,4GHz range and the WiFi signal can be seen by a laptop.