How to have many sliders and slider below the header?

Hi,
I am using wordpress for the development of website. I searched for themes. I have installed the Sydney theme. Now the problem is we can add only five slides. But if we want to add many slides then how could we achieve this?

Also, the header containing the name of organization and menus are on the sliders. I dont want this. I want the the header should contain only logo and name of the organization and the menus and that too the header should be fixed. After the header slider should be displayed.

How to accomplish this?