I recently set up a 15 hikvision cameras for my home and am very happy with Umbiquiti network hardware. I bought their edge router pro, edgemax 24port 500w and unifi 24 port 250w. Ubiquiti also has IP cameras, but they didn't appeal to me so I went with Hikvision. Ubiquiti also has a large and helpful online community if you need help configuring things.
the UniFi line is nice if you want a web app to monitor the network and the EdgeMax line is more "pro" it don't use the web app controller, but it does have a nice GUI to administer it. Personally, I use the UniFi for my homes LAN and WiFi(three UniFi access points) and I use the EdgeSwitch for the IP cameras.
I have been researching my first IP camera system. I am looking at an external switch. Using a self-contained NVR with internal switch will mean that changing its location would be difficult down the road. By using an external switch, I can place the switch any location that makes the most sense for the camera wiring, and then run a single cable from it to the NVR. Moving the NVR is then much easier and does not require touching any of the cables from the cameras.
The switchless NVR models are a little cheaper, so the net cost is not so different. This may also mean a quieter NVR. Switches are available that are fanless and are therefore silent.
I use Poe switches for power purposes. In the event a thief makes it out with my NVR, I know that my cameras still have POE power via a seperate switch and so the cameras are still recording to the memory card inside the camera