@ OP
Unfortunately the DVD analogy is flawed as all DVD players will play a DVD, and all will play that DVD by you pressing the identical 'play' button the the remote.
As you say the differences are clear.
However, with a CCTV system the equipment differences are just the start of it. Its not about what you like the look of, the coolest brand, or what the man in the
shop recommends as it will depend entirely on the minutiae of your premises and your needs. It is often not possible to give advice without knowing what it is
you are trying to achieve and what your premises looks like.
This is all before we have even considered how you are going to connect it all up, which, I hasten to add will be a bit different to connecting two HDMI leads.
You keep assuring us you are competent to connect it up, but that is rather like me saying I am certain I can drive a tank, I just need someone to tell me the best
one to get.
I am not sure what you mean about the decline of the UK security industry, It exists by supplying services to paying customers, unless I grossly misunderstood the
game plan here?