Good day fellow sparkies!

I am currently working on a quote for a job on a private estate. A security company needs to install cameras around the perimeter (L-shaped) which is 1.2km (600m + 600m).

In total it is 24 cameras (50 meters apart). They require a plug point on each pole (inside an IP65 rated box). The power will be drawn from the security cubicle at the front gate, which has a DB.

Here are the camera's electrical specs:
Power Supply DC12V(±30%), PoE(802.3af)(Class 0)
Power Consumption DC12V:2.4W 7.1W(IR on)
PoE:3W 8.4W(IR on)

What cable and size should be used to supy the points (to compensate for volt drop)? Also, is it allowed to have all 24 points on one line? (Seeing as running multiple lines will increase the cost exponentially). The points will be mounted high up on poles, so they won't be accessible for anything else except supplying the cameras.

Please inform me on the correct regulations which may apply.

TIA