I am trying to design a built in media wall for my living space, and I am conflicted about what I should do at the right end of the soffit wall I built (by the 2 windows)

Here is the current layout

and this is what I am thinking of building

I would love some advices and input on the over all design. Here are of my open question:

• What I should do with the space by the window. I have some ideas

1. End it the way it is in the photo and put some chair or furniture there
2. add some built in cabinet that would go up to the window and have a reading nook there

• How tall should the cabinet be? 80" or 90". the wall is around 11' tall