Why don't you just get the CCTV / Intercom / Gate guys to quote an enterprise grade Wifi system for you and work with the main con? That way you can
(1) have an optimal and secure location for all your CCTV recorder, NAS, switches, etc,
(2) ensure all the concealed cabling is run properly (these things take up space) so it should be planned and budgeted now, and
(3) they can advise where is the best place to put the APs, how many and why, what kind of switches, etc. you can even have everything terminate in a server rack.
You have a clean slate and it makes sense to focus on the backbone of the system - the APs themselves will likely change with time due to tech becoming obsolete etc but that can always be changed later. Frankly, mesh or no mesh is a minor consideration in the long run. and the AP won't look very different than say a smoke detector but the coverage would be better
