I would look for a sofa you like and then choose 2 accent chairs. Do not get a sofa/loveseat set. You did not indicate whether you are looking at leather or a fabric sofa. If you get leather, then the chairs should be fabric or visa versa. Do not get all leather pieces. All fabric is ok. The chairs do not have to match, unless you like them enough to buy 2.

If you can give me a bit more information about what you are thinking or what your needs will be for seating in the room, you will get more help. IF you want to have help in arranging furniture in the room we can do that also. Once your major pieces are in the room, then decide on rugs and accessories.

The rug is the major piece in a room and should be your first purchase. It is harder to coordinate a rug to upholstered furniture than upholstered furniture to a rug.

Medium brown with slight red tone:

Simon Li Furniture Sofa, Ebony · More Info

I see you have green. French country a bit:

Beth Sofa · More Info

Given your space, let in natural light can help you lighten your dark room. Along with this, a neutral color scheme for your room will not only complement the natural light coming in your room.

Coming to the furniture, a minimal sofa set would look wonderful in your room. It makes for a great sitting space and offers you make the area look more spacious. You also get a lot of room to move around. You can browse for such sofa set online. IKEA has a great deal of trendy furniture which acquire minimum space and promotes simplistic designs. They also have a range of color coordinated accessories which will help you enhance the overall look of your home.