How about a picture of your couch to see the design. Traditional and modern.

UPPLAND Armchair, Totebo light beige - IKEA

EKENÄSET Armchair, Kilanda light beige - IKEA

Here are pics. The room is quite empty. We had downsized, then bought this big house. The room is 16x30.

The first chair I pictured will go easily. Even two. One or two Ikea ottomans can be pushed up against the couch for a chaise effect. Works for tv watching. Ottomans also work as coffee tables for snacks on trays. You can do a graph paper scale of your floorplan with cutout scale furniture Easy way to see different groupings.

Love your couch, if it's not rude to ask, where did you get it?

@mmkirkaldy, thank you! Hope you find chairs that fit with it!

Is is the style or the fabric that you are having difficulty choosing.

If it is style, your couch is fairly neutral in style so I would focus on functionality and taste. Based on discussions with my designer when I redecorated, you might want to counter the boxy shape of the sofa with curved lines. For example, I have a rectangular sofa and so after much consideration I chose a very classic barrel shaped pair of chairs (swivel) as a counter point.

Similarly with respect to the fabric. My sofa is a very deep blue but not navy. A solid fabric wouldn't have worked because it was have been too close but not close eough - besides being visually boring. I went with a leather in a blue that picks up some of the color nuances of the velvet sofa - it is a different material and a different color so it doesn't match but it seems to complement choices.

I didn't want to go with a pattern which might be a great choice for you since you have all solids so far as I can see. In my living room I have a very distinctive Chinese Deco Rug as well as a patterned vintage chair and so I didn't want to bring another very strong design element.