Mega-Pixel security system. should i get BNC or POE ?

I currently have analog BNC set up. I want to get a new system with Mega-Pixel cameras.

I was able to find analog BNC 8 ch 4MP camera system for $450 w/ 8 cameras (https://www.costco.com/.product.1112561.html).

I found a POE system 8 ch 4MP camera system $600 w/6 cameras. Audio in all.

(https://www.samsclub.com/sams/8ch-1080p-nvr-8x4/prod16050413.ip?xid=plp:product:1:5)

I am not sure which one is better to get? Audio in all cameras would be good but for the price I dont know if its worth it. Will I see a difference in these two? When I zoom will I get same clarity on both? or what about sharpness of the face or license number?

Please help

Since you've already got coaxial cabling in place, I'd get the first system. The second system would require you to run cat5 cables. As far as seeing faces and plates, that all depends on distance and angle to target. It can be difficult during the day and almost impossible at night (unless you get a special plate camera). As you zoom, the picture will get less and less clear. You have to get a very high MP camera to be able to zoom with no loss of clarity.