For a shop counter, I would focus first on getting a clear view of the customer, sales counter, and payment area. A camera with suitable viewing angles and good low-light performance would be more important than simply choosing the highest resolution. For the ZoneMinder setup, running the capture hardware directly on the Ubuntu system may be preferable to using VMware, since PCI capture-card passthrough can be problematic. An IP camera could also be worth considering because it avoids the need for a PCI capture card. For general guidance on networking and CCTV-related hardware, you can also check IT Hardware solutions.