Reddit reviews Ubiquiti NanoBeam ac 16, Compact High-Performance airMAX Bridge 16dBi (NBE-5AC-16-US)

The NanoStation line is End of Life and considered legacy. It will still get updates if there are major security concerns, but the product is very old.

You would have been better off going with a pair of NanoBeam ACs:
https://www.amazon.com/Ubiquiti-NBE-5AC-16-High-Performance-airMAX-NanoBeam/dp/B019PDI6OY/ref=sr_1_2?ie=UTF8&qid=1505612077&sr=8-2&keywords=nanobeam
They offer much better speed and performance.

Fiber would be the best option, if you're willing to run it. For personal/friend situations, I have purchased pre-terminated fiber and just buried it a few inches below the ground with a shovel. You can get the fiber for about $70, two SFPs for about $9 each, and two Ubiquiti Fiber POE modules for about $30 each. That would get you a 1gbps/1gbps connection between the two buildings. The Fiber POE modules convert the fiber connection to regular ethernet.

The LocoM5 is getting a bit long in the tooth, isn't it?

A Nanobeam AC shouldn't cost much more - Gen1 16dBi is $77 on Amazon, and there's a handy suction cup window mount if you can't/don't want to drill holes in anything.

NanoBeam AC is functional at -40. And you can grab a pair on amazon for about $200.00.

https://www.amazon.com/gp/aw/d/B019PDI6OY/ref=mp_s_a_1_1?ie=UTF8&qid=1481836560&sr=8-1&pi=SY200_QL40&keywords=nanobeam+ac&dpPl=1&dpID=41OJP0XymAL&ref=plSrch

Would do the trick but you’d be paying an uplift for the “preconfigured”

I’d probably recommend you configure yourself so you know how it works in case things go south in the future

https://www.amazon.com/dp/B019PDI6OY/ref=cm_sw_r_cp_api_i_6XuaBbGMMDAHE

I would suggest a pair of the Nanobeam ACs, would be much faster than Loco Ms

https://www.amazon.com/Ubiquiti-NBE-5AC-16-High-Performance-airMAX-NanoBeam/dp/B019PDI6OY/ref=sr_1_1?ie=UTF8&qid=1504136312&sr=8-1&keywords=nanobeam+ac

I've got a pair of these spanning a parking lot without any issues whatsoever.

https://www.amazon.com/Ubiquiti-NBE-5AC-16-High-Performance-airMAX-NanoBeam/dp/B019PDI6OY/ref=pd_sbs_147_3?_encoding=UTF8&pd_rd_i=B019PDI6OY&pd_rd_r=DHJ3AT2KFXSJEH060GCG&pd_rd_w=XLFFl&pd_rd_wg=REvgN&psc=1&refRID=DHJ3AT2KFXSJEH060GCG

I have them mounted on the roof of the 1st floor. There is a little bit of tree cover between them. They've been rock solid and report >400mbps consistently. I've never had a single complaint from the clients on the remote end.

Yes, that helps greatly.

First, being unable to acquire additional IPv4 address is unfortunate. The additional address would have greatly simplified the overall headache involved and allowed each residence to essentially have their own standalone internet connection with whatever portion of the fibre bandwidth you allocated to them. Without them you can still do it, you're just looking at NATing your single IP to all the devices which complicates things such as port forwarding, introduces the possibility of dual-NAT configurations, and increases the likely hood of that shared IP being abused and potentially blacklisted on a service because of the actions of one user affecting the rest of the users.

I would suggest a pfSense (or OPNsense) gateway hooked up to your modem or ONT, this will handle the NAT, VLANs, DHCP and traffic shaping. If you don't buy or build a pfSense box with at least 8 ports, hook this up to a managed switch. One line run from this to each of the wire-able units on your attached building plus one to the roof for a wireless AP.

Because the distance across the road is short and looks to be mostly clear LOS with sparse trees - you can approach the wireless AP a couple of ways. If you plan on only offering a 100Mbit/s or so to each "customer", you could get away with 3 Ubiquiti AirMax NanoStation Loco M5 units. One on your roof to act as the AP and broadcast the signal across the road and 2 on the other building across the road for each unit. Just easier to put up a receiving station at each unit that wants to join vs sharing a single one - I can get into the reasons why if you'd like.

If you're planning on providing more than a 100Mbit/s to each person than you can consider the same setup but substitue for the newer Ubiquiti NanoBeam AC units for a slightly increased cost.

It is also possible to do this all under the Unifi umbrella if you so choose. It is slightly more costly but is definitely more user-friendly and easier to manage under one interface. Here I would suggest you replace the broadcast AP with a Ubiquiti Unifi UAP-AC-M-Pro and each receiving station with a Ubiquiti Unifi UAP-AC-M. Note these are omni-directional antennas now, they lose the benefits that come from directional APs but at the distances we are looking at here that should be a negligible difference.

A real rough hierarchy layout here: https://i.imgur.com/QV0qfq6.png

Each individual unit is isolated from each other and you by being on their own VLAN, to which you will configure only gateway access on each VLAN with no cross VLAN routes.

When it comes to what is happening on each units internal network, you can do one of a few things. You could still allow them to use any ol' router they choose, hook up to the WAN port on said router and NAT their own internal network. This will work fine, albeit behind double NAT, it will take a good portion of the internal routing load off your pfSense box and only involve it when the client needs to get out to the net. Or you could handle all the internal routing and just have them use a switch and AP (if they want wifi in their unit) - you could get real fancy with this way but it adds a lot more potential for trouble on your part, the other option is likely the easier one.

Lastly, regarding authentication, you could take it one step further and utilize the PPPoE server on pfSense to give each unit their own PPPoE username and password they need to use to authenticate against your router. No username and password = no IP = no internet. Useful for revoking access to one user who doesn't pay their portion without having to physically go over and unplug them.

Sorry for the wall of text. These kind of setups are fun and I've dealt with a lot of similar setups for different applications.

Point to point wireless

Ubiqiuiti Nanobeam would do the trick. Probably more reliable than powerline.

Two of these: https://smile.amazon.com/dp/B019PDI6OY/ref=dp_cerb_1

Think of them like a wireless extension of the ethernet cable. You'd still need a PoE injector after the receiving nanobeam in order to power the camera.

Yep. I was going to use:
https://www.amazon.ca/Ubiquit-Networks-Nanobeam-High-Performance-airMAX/dp/B019PDI6OY/

Do you know what sort of speeds I could expect with the 900mhz?

I don't know why I just keep focusing on installing a utility pole and mounting a pole/ antenna to the top of it. But sounds like thats not possible.. Unless perhaps I somehow managed to get ahold of some crazy tall utility pole like 60-80 feet tall. Then I remember theres a HUGE tree a short distance in the woods that I'd guess looks 100' tall. If I could manage to mount a pole at the top I guess that would work as long as its not too tall?

Heck Im a dummy maybe the trees arent even as tall as I think they are :P The guy at the hardware store yesterday seemed to suggest that theres no way the trees could be 60'-80' tall.

Im getting a drone today. I'm just hoping the trees dont get too much taller along the way. But that 900mhz might be worth checking out :D