Hey @genesis77,
Though it’s possible to overlay your header by using custom CSS, it’s not recommended for your setup as you can see the result in this screencast: https://youtu.be/NYmwRUtfS1g. In case that’s what you’re after though, here’s the code from my demonstration. Please just note that the code is for demonstration purposes only. We do not give custom code as part of our support service.
/* apply to your home page only */
.home .masthead {
margin-top: -90px;
}
Our sales page design is not an overlay. The slider’s height is reduced taking into account the height of the masthead. That was made possible by Slider Revolution’s Fullscreen Increase/Decrease Fullscreen Height option. Just insert the X header’s class which is .masthead
and it will automatically reduce the slider’s height.

That will work for Pro header also. And regarding the difference between X and Pro, the major difference is the ability to create a custom header and footer and assign it globally or per page, post or custom post type.
If you need the demos in https://theme.co/x/demos/ though, that is only available in X. Pro has a different templating system which is the Design Cloud. For more details, please see https://theme.co/designcloud/
Hope that helps.