Can you show pictures of the wall and fireplace and the rest of the room? Decorating on a budget forces you to think creatively, that's good. One thing I want to say is just because you have high ceilings doesn't mean you need to decorate "up high". First, you should concentrate on getting the space you live in right. Don't focus on the high wall until everything else is right in the lower part of the room. Rugs, sofa, art and lamps should be your first priority. Chances are your high wall won't even be an issue. Please add pictures of your room.

The pic of the room... I thought drapes maybe enough.. but

I'd go to 3 or 4 art galleries and look at some really nice paintings. Find an artist you like and have the gallery bring several paintings to your home to try above the mantle. They'll do this at no charge. Look for paintings that have the style and colors that work (not necessarily match) with your walls, furniture the mood you want to create. You have a wonderful place to make a statement. Just for a guide line think of a vertical piece with the width being no larger than the opening of the fireplace. The personnel at the gallery can be a great help with size and framing. This is just an idea since I know nothing of your style.

Swipe over the painting to see the whole picture. For some reason it's cut off in the middle. You need to concentrate your decorating on the room including the couch, rugs, lamps and tables. If you get your room right the height of the fireplace will be like a background not something you have to "do something" with. As a guide the picture should be hung in the space made by the wood work--not lower or higher than the bottom & top of the middle section.

Maybe something long like this Deco sconce?

We have a wide variety of sconces: http://www.hubbardtonforge.com/ProductsThumbnails.cfm

May I suggest no sconces, but a large chandelier, hanging much like this picture. I would prefer to see to see the light reflecting off the paneling than up the paneling. Bad description.