In all likelihood, you can pull the video feeds right from your NVR into it.
In BI, you select add camera and put the IP address of the NVR into the IP address location. Put in username and password and hit find/inspect and let BI do its thing.
Then about halfway down is a pull down for Camera number and pick camera 1 and then hit ok. The camera should show up. Then add camera and the select copy and copy this camera and then change the number 1 to a 2 and repeat for your cameras.
So download the BI trial (hit demo instead of keying in the license) and give it a try and see if you like it better than the NVR.