Hi
First of all i feel the 8 channel NVR you mention is to small. Go for a 16 channel minimum.There is little price difference. The other option is a PC running
blue iris. There is no real limits on the amount of camera's you can run providing the PC is suitable. See The
wiki.
With a POE IPcamera audio,video and power is via a single
cat5e/6 cable.
Wiring you have many options available and it really boils down to the specifics of your site. My order of preference below
You can run a cable from each camera back to an NVR or POE switch in the house.
You can run the cameras to a POE switch in the garage and a single cable back to an NVR or POE switch in the house.
You can also run the cameras to a POE switch in the garage and use a power line adapter.This will run the computer data network over the existing mains electrical wiring. This will again go to a switch in the house.
You can also run the cameras to a POE switch in the garage and use a wireless link (this is a link capable of coming with the volume of data generated by the cameras and is not wifi) Other members here have used something called a nano.
I'd only recommend using Wi-Fi cameras as a last resort. You will still need to power them up.
Good luck