First question is, are the place you want to connect in generally the same region..say about 85 dgrees or less degrees for the mounting point of the AP?
If yes, then SXT SA5 /sa5 AC would be fine with the SXTsq Lite5-US.
If no, then you can look into the omni directional offering for Mikrotik, RBOmniTikU-5HnD-US or RBOmniTikG-5HacD
For wireless AC to work, of course you need AC receivers sxt lite5 ac, for example. Wireless N will work with any either AC or regular 5 Ghz AP from Mikrotik. The higher rate of speed won't matter if you get the "lite versions" of receivers as they only have 100mbps Ethernet ports; the radios are capable of 300-866mpbs data rate speeds which means you should easily get a wire speed of 100Mbps.