Hi Bolshoi,
I thinks it's recomended to use NVR but maybe need more cost. But if we see from the effectiveness, the IP system is more powerfull and simplivity.
Using NVR, IP camera, POE switch, and for the backup it's need the small UPS around 800 VA.
For the cloud, you can integration the NVR device such as dahua and hikvision with cloud platform (Drive, Dopbox, etc).
Hope can solve your question.
Thanks,
Fathur.