I would certainly save a pretty penny if I skipped the panels :) However, at night and most days in the winter when the blinds are closed to keep some warmth in, the room and that wall needs a pick me up of color. (See pic below.) But I agree with all of you that I want to cover the windows as minimally as possible and just have a panel that fills the space of white wall board between the windows and at the ends. They will never close, just be stationary. Here's an updated picture of the room with current furniture. Need a coffee, end and sofa table and something for the wall on the right. The final panels would go to the floor not 3/4 as in the picture. The sample fabric I bought is not long enough. I'm liking @terriks idea of back tab panels as well.

2-50” panels are plenty if going to be stationary not used to open and close for privacy. Hang the rod up as high as possible or just under crown molding....also hang rod about 4” wider than widow on each side...

It looks as though you don't have room for drapes of the windows by the fireplace. Perhaps you can do Roman shades there and on the door glass door and matching drapes on the windows. I like your rug but unfortunately the pillows on the leather couch aren't a good match. Blue and white patterned pillows would be perfect.

Before you worry about curtains you should properly hang your stained glass panels. The way you have them now looks weird and takes away from the beautiful glass. Screw 2 hooks on either side, inside top frame of each window and hang your panels from them. As for the curtains, do you need them? Because your glass panels have now blocked the windows, your room appears dark. Old traditional houses that have small stained glass windows on both sides of fireplace don't usually have curtains on these windows.