I can understand the frustration at the thought of obscuring the sliding doors. To avoid that you might consider a pair of sofas that face each other. (Like in the picture attached) This position looks very welcoming as it invites the seated people to face each other for conversation. It does mean for viewing the tv on the 'blank wall' you won't be in the most comfortable position, so I suspect you'll need to compromise somewhere... Access to the door against tv viewing.

I have loved our deep leather lounge for the same reasons that many have stated above. You literally "lounge" and when I had a shoulder operation it was the perfect bed for recuperation, giving my shoulder support while, at the same time, giving me a comfortable and easy sleep. However, as I have aged, and also due to my small stature, I am finding that my back begins to ache because the back of the lounge does not support my back firmly enough and my feet don't touch the ground. I am now looking at a smaller, upright and supportive type of lounge. I do have a couple of chairs that fit this but it means that I am not sitting cuddled up to my husband.

2 sofas look great when you are needed extra seating for people but i really like the armchair /wingchair idea with a sofa. As you have chosen a modern take on deco i would look at a side table that encumpases that style but as said functionality is key. No good having one sofa if you have 5 guests. It sounds so beautiful so keep moving with your ideas and remember that sometimes ideas can change with different advise but you have to love it

How many people do you want to seat? Is that a walk through beside the stairs? Is there a view out the window? My first instinct is to say two sofas facing each other so everyone can see out the window and enjoy conversation.