Yes you can run a network cable cat 5E / 6 from the NVR to the attic where you place the switch. The switch needs to be a POE switch or you will need to have power injectors.
I have a Hikvision NVR that I got from aliexpress. I have 2 2CD2032-I cameras connected to it I would like to get 4 more cameras. It looks like the 2032's aren't being sold anymore. I was looking at getting DS-2CD2035-I, but one of the sellers says it will not work with my NVR and firmware...