Need help choosing a long range router

Good afternoon, habrozhiteli, I really want you to help me with advice on what question:
There are two school buildings in direct visibility, about 50 or more meters apart. It is necessary to connect them by air and provide both buildings with Wi-Fi (the maximum distance is two floors diagonally).
What is:
1) Both intended locations of access points will be on one (second) floor.
2) Hanging the wifi on the street is difficult
3) The signal is likely to go through a brick wall, glass, air, glass

For clarity, I will attach the scheme of the intended connection:


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Box 2 will be located there, because it will be so. The first one can be moved, but there is already a way out to LAN (I understand that it would be more logical to put opposite “2”, but then you have to carry extra wires).

Now I am in the process of finding solutions. The price is not so significant (maximum 10k apiece). Accordingly, I really want to hear your suggestions on how to provide both bodies with Wi-Fi (in our conditions it is easier to scale).
I look in the direction of TRENDnet TEW-631BRP or something like
TRENDnet'a TEW-639GR . I will listen to any suggestions and advice, and I will also give a lecture on how to organize it all better :)

PS: I have an idea to put a directional antenna on "1" router instead of one removable one - like here in l2k . Maybe there are some tips? The budget is again not so critical.

PPS: we do not beat strongly with the feet of a neophyte, it is better (if necessary) to offer where to move