I'm an end user that self-installs take it from me, hire a professional, you may end up wasting money on the wrong cameras and equipment.
Pay attention to VMS licensing too some will count multi-headed cameras as one some won't.
If you insist on doing it yourself, Axis Site Designer is a nifty tool
The Set up I'm building for our new retail store:
Fortigate 50E, I was going to go for the 30 (Because I'm cheap) but the 50E has lower latency and dual WAN so I can run a 4G backup.
2x Aruba 24 Port 2930F Switches (Stacked for redundancy, instead of one 48 port if one fails my whole system wont be down, also if you go this route always buy from an HPE authorized reseller they will not honor a gray market warranty. HPE has perpetual lifetime support)
Supermicro X11SCA Mobo w/ Xeon E3 in a 2U 8x Hot Swap Case running RAID 10 + Hot Spare (5 HSGT/WD Ultrastar Drives Total) on an LSI Mega Raid (I'm using Axis VMS because I bought it with the analog encoders a looooong time ago, I would most likely use a VMS that would run on Linux because for me Linux is easier to Admin)
Siemon Z-Max Patch Panel and Z-Plugs.
Eaton 9PX1500 for power quality and backup power
Windy City Shielded Cat5e Plenum (Because it is thinner), I based this on IPVM's test I was originally was going to got for Hitachi
5-6 Axis M2026-LE MkII (Because I'm a cheapskate, I remember paying 500-600 for M Series Cameras years ago for our other location)
Axis FA54 with 4x 1080p Dome Units for exit doors
Axis F34 with 4x 720p Bullet Sensors for Stock Area
Supermicro 1U Atom for PBX for phones and for the Intercom
Whatever Synology NAS I have lying around for backup, plus cloud backup to Backblaze.
For Going Outdoors:
Axis T8508 Switch mounted far away from the IT closet connected via fiber to isolate from stray power surges, Switch also has surge protection on each port
DIN Rail Mounted Siemon Patch Panel
L-Com Surge Protectors at each entrance, grounded.
Eaton 5S UPS
Outside Construction Keeps Changing So I just picked One Camera So far
Axis P-3228-LVE 4K for covering the front and street
2N IP Force Intercom
I recommend also lurking on Reddit Networking because the cameras are only 1 part of the puzzle.