@zm10 has not replied or visited the forum, shortly after he wrote the question, he has not checked anymore,
perhaps he has given up or has already made a decision, HOWEVER, for those who read later...
@zm10, the silliest thing you can do on city is put a high gain antenna:
It's in the city so densely populated.
He also gets all the surrounding signals, which for sure in a densely populated city, as he wrote, will not be missing.
A very directive antenna is needed, preferably with little gain.
It has not been specified how much it is necessary to bring to 3.3Km, so a SXTsq could be enough,
but for a better choice it is OBVIOUS that you need to know how much bandwidth in total, and a spectral analysis if there are free frequencies.
In many states it is STRICTLY FORBIDDEN to transmit between two funds (whether they are own or not, it doesn't matter)
by hovering over other public or private properties, or by radiating unlicensed signals outside own fund.