Video editing with audio layover

Hi ,
I have some CCTV footage that runs for around 4 minutes, it is of a customer of ours who passed away, this footage is going to be given to his family, so i have footage of the gentleman entering our store, having a conversation in-store for which camera number one has audio recording, this audio recording from camera number 1 is to be overlayed on all of the camera footage in side the store from other cameras we have , so we capture the voice on all camera inside the store and it should play in sync with the camera one, and on the external footage we want the national anthem for liverpool football club to be playing .
We also would live some text and still images created from the footage at the begging on the video , so it is a nice sentimental memory for his family , we would like this to be played on a loop recording , lets make this really nice for his family