the right access point it cant be done, its vastly different than 50 laptops hitting the internet.. thats intermittent and easy to share; this is persistant.. its like trying to get 25 laptops streaming netflix/youtube 1080p at the same time and never buffering, 24h a day, 7 days a week, 365 days a year... without interruption.. good fucking luck, never gonna happen.. you'd have to break the laws of Physics.
25 cameras streaming 24/7/365 HD Video is gonna need about 6 access points, and you have 3 channels to work with so it'd take very carefull design, setup and then it'd still be pure shit and unreliable.
None of the cameras are AC/N, they are almost all 802.11G and that is even more impossible as it makes the AP's run in compatibility mode and the entire networks performance is going to go right down the toilet.
Great high end enterprise access points start falling apart once you get beyond 3-4 HD Security cameras, WiFi is a large part of my career and I am a licensed radio operator.. I kinda know this shit.