We have installed a few Ubiquiti UAP-AC-M-PRO access points (never needed to Mesh them) so not sure how that portion works but I would also recommend if going this route getting the Cloud Key. This will make life much easier to configure all the devices to work together and allow for easier setup of SSID and passwords.

The biggest issue I have found is that the Ubiquiti APs don't like to have static IP addresses (not sure why, but could never get them working with a static), so using DHCP with the cloud key you don't have to try and find all the devices.