I'm pretty new here but I like helping people out. From what I understand the IPC-HDW5231R-Z is the best bang for your buck IP Cam, especially for it's low light performance.
NVR would be recommended for a majority of the people. More reliable than windows, cheaper vs buying a high performance machine, plug and play. More than likely you will have less headaches with an NVR and it will generally last for years without issues besides maybe needing to replace a hard drive after X amount of years.
Dedicated PC if you already have a powerful machine that can be dedicated for software such as
Blue Iris. In this case this route will be cheaper. I feel that Blue Iris has an advantage in that it is more flexible in how you can configure it. But I am biases as I have never used an NVR.
I run several R710's at home and I love tinkering and configuring servers as I am a Systems Admin, so naturally I went with a windows box running Blue Iris. Going to be adding more drives in a RAID 10 array soon.
Cameras with a SD card do not require an NVR, such as IP cameras that don't have an SD card do not require an NVR. Basically if the IP camera didn't have an SD card you don't have to buy an NVR, you just won't be able to record anything.
That being said an NVR will give you a single interface to record, manage, view all of your IP Cams at once. It's not recommended to use an SD card as primary storage as someone could easily destroy or steal a camera and there goes your footage. SD cards are also less reliable. What I do is record everything using Blue Iris and also record everything via SD card. This way 90% of the time I can go to my server and pull footage. Let's say my server rebooted, then I could pull a clip directly from the SD card.
Hopefully this helped you out a bit.