We have been renovating a 1980s modern home. In the process, would like to replace the existing exterior door and windows with a large sliding door. Would like the door to be taller then the existing standard size door and aligned with the window heights, but the header is preventing us from going higher/taller. Could you use a steel beam with narrower width as the header to gain height?

This is a two story house. As shown in the pictures, it has 4 2×6’s for the top plate followed by the header for the door.  The existing windows butted up to the top plates with no header.  Pictures attached.

Looking for some advice or ideas
Thanks