Which is the best Cloud Service for CCTV footage?

Hello community, 

I am the CTO at a small tech services company.

Which is the best Cloud Service for CCTV footage? I.e. data from NVR for a small setup of 16 Cameras thus a 16 Channel NVR. This includes camera models, Dahua, Hikvision, or UNIVIEW 2pm and 4pm.

Thank you for your help.