[jcrawfordor]

Any normal surveillance system. E.g. an Axis IP camera with ZoneMinder (not that great but FOSS) or one of several commercial network video recorder (NVR) options running on a machine somewhere. Ubiquiti even makes IP cameras and an NVR appliance now. Any decent NVR will also support remote video streaming, you might need to configure your network appliances appropriately.

Don't do analog. It's cheaper but it's not really worth it, you should get at least 720p these days (that means IP) and I'd reckon analog equipment won't be easy to buy for very many more years.

Don't do wifi. You need to get power to the camera anyway, so run ethernet with PoE. All these WiFi surveillance cameras are crazy, jammers are pretty easy to obtain and burglars are going to start using them. In a business installation, you should segment the cameras from the rest of the network, with VLANs or separate switches. Dual-home your NVR or lock it down at a firewall. It's just good practice.

The current trend of cloud-based surveillance is something I find very strange. It's more convenient in some ways than a local DVR or NVR but that comes at a big cost, including often monthly service fees! I think it's really only because of a lack of sufficiently consumer-friendly NVRs. There might be some money there for someone who takes that on.