You said you run fiber from network switch to NVR.
You will need SFP module to connect fiber to the network switch. The TP-link switch mentioned in your post already has 4 combo SFP slots. so you should go for it.
One more point - I checked datasheet of SRN-4000. It has only ethernet connector available. so, how will you connect fiber to the NVR?, you will need a fiber to ethernet media converter at NVR end.
Managed switch will have more features, with capability to manage each port of the switch idividually. so, if not much price difference, go for managed switch. however, if it is a military area, you should make sure all ports are secured post-installation.
