Help with Setting Background in Vantage Theme

Hello. We need help in creating a very professional looking and enticing background for our homepage and sub pages, We were looking to have a nice Fixed image at the background and a little video playing in the middle similar to this site ( ). We just want to know how they did these kind of things and so that we will be able to do even better. But we would like to keep these things in mind.

1. we would like to have different background images for all our sub pages.

2. we would like to have the ability to set small videos as headers or semi background to specific pages that we have.

3. that all the images in our sliders or video players have the same appearance in all devices or screen resolutions.

Thank you.