PtMP question- what would you do?

I was looking to setup a PtMP network with Ubiquiti products and had a few questions I was hoping someone could help with. The network is to be able to view cameras at multiple sites. There are 5 sites altogether; one which would be the base station, and 4 other locations. The 4 locations are 0.1km, 0.6km, 3km, 3.6km, in a suburban environment. The 0.1 and 0.6 have direct line of sight, the 3 and 3.6km sites might have some taller buildings in between them and the base station.

Questions: 1) What ubquiti (or other brand, I’m a networking newbie) products would you use for the base station and the 4 other sites? 2) Right now I have internet access at the base station site. If in the future that access becomes unavailable and I can get internet access at another one of the sites, can I reconfigure the setup so as to use the internet at one of the other 4 sites but to use it for all of the sites?

Thanks in advance for all your help.