If you want useful -- I highly recommend a small table with two chairs in the one end. Also, bookcases with glass fronts, or, like I did -- one bookcase and one secretary that closes up to hide the paper and computer monitor. I use my 36" square table for so many purposes -- morning coffee, afternoon tea with a friend, making jewelry, drawing, computer, solving jigsaws. Mine has two leaves that pull out, so I can also bring chairs in from the dining room if I want to have four people in the space. My space isn't crowded. There's at least 4' of space between my table and the rug. You're fortunate to have fewer doors and windows, and a 15' width. My 1939 living room is 12' x 21', so it's divided into three spaces instead of two. My secretary and bookcase had to be on the other end of the room.

I like those chair choices and think a swoop-arm chair would be a nice accompaniment to your sofa. However, since your room is not large, I would make sure that the new chairs' footprints are no larger than the ones you are replacing. Regarding the furniture placement, I agree that the sofa should be placed on the long wall flanked by the two chairs. Hang decent-sized art above the sofa and add coffee and/or side tables. If both the china cabinet and buffet need to stay, I would then switch their placement, giving weight/height to the opposite side of the room in counterpoint to the sofa and art on the other side.

Depends how do you want your room to be perceived. Let me explain - with the L shape the arrangements works well for a cuddling family, not for the inviting friends (from the entrances these sofa's backs do not look remotely inviting. Works for a TV time with family, but not for the guest gathering/conversation thing. You'll have to take into a consideration how much longer your kids will remain cuddly, because in teens years they are rarely sit shoulder to shoulder. 2 Sofas look nice, but don't do sofa sliders - to be able to have a nicer/bigger coffee table (you would need at least 18" between the sofa's edge and the table, and at least 30" between the window and the back of the sofa), 2 facing sofas are not convenient for the TV viewing - unless if it's a sofa per person and a person is laying down. Like how the room is claimed with the 2 facing sofas - much less of the unused floor. You'll need a much bigger rug though to ground the furniture arrangement.

Thanks everyone, appreciate the input! @Patricia -- I know the chandelier isn't a perfect match, I stupidly fell in love with it before buying any of my other dining room furniture. BUT on the other hand wasn't drawn to any MCM-y fixtures prior to discovering this one. I think since we already have an eclectic vibe, it complements the rest of the decor fairly well. @Patricia & Ida -- ditto to the "no one wants to see themselves eating" comments. My sister said it to me yesterday.. Since we have a relatively small space, I thought a mirror would give the illusion of more space and brighten things up a little. And like Ida said: classic element, reflect the pretty chandelier, etc. I'm thinking I either need to borrow or buy a rectangular mirror just to see what it looks like. If it's terrible I know I need to go in the direction of artwork, maybe gallery wall? Wanted to avoid that because then I'd have to put together a cohesive grouping of artwork and photos. :\ I was considering a round, tinted mirror but am afraid I'll strike out again. This one is amber, also available in rose or grey tinted.. What about a starburst mirror? Sorry I'm stuck on mirrors, again, small / darkish dining area, trying to brighten it up and give the illusion of more space.