Divide and Conquer?

For weeks I've been struggling with how to arrange our newly renovated dining/living space. We will no doubt need new furniture as most all of ours is hand-me-down, but I certainly don't want to take the plunge and get new pieces until I have a solid idea of how the space will best be setup.

See the problem is that it is a long, narrow space (26' front to back and 13' (ish) width in the living space). Since it's one large space I'm finding it a bit difficult to find a great solution to not only divide the rooms to distinguish the spaces, but also make them cohesive and work together.

Here is the space I'm referring to:

Since we've lost our camera I'm forced to go with an older picture of the space, but you get the idea. The buffet has since been moved under the windows to the far right and the two couches now sit opposite one another in the living space along each long wall. 

My thoughts on dividing the room include these options:

• A tall white chunky bookcase that is see-through that would butt (perpendicularly) against the far wall. Something like this perhaps:

Then two substantial chairs in the divider space with a small end table between the two. I'm thinking this Zora chair with a bit higher back, but not completely wing back like. Obviously it would NOT be this fabric! It would have to be something that coordinates with my lovely Hip Berry pillows of course (below).

• Or something that sits more in the middle of that divider space. Maybe a long, narrow white bookcase on it's side again with the two chairs in the living space arranged as suggested above? Then maybe hang (eeks, Michael hates this suggestion as we just got beautiful, smooth ceilings in this space) cutout screen decor panels from the ceiling the width of the bookcase (really the height, but laying down would be the with):

I know, hard to get the idea with these, but they are white plastic with laser cutouts. They come in all kinds of different patterns. You can hang them from one another. 

The good thing about either option is they would both look good from either the dining or living space. The goal is for the spaces to still allow for conversation between the two and not completely separate them since that was the original goal in knocking down the walls!

Any other suggestions?