I will, however, give you a third option to think about: If you absolutely must have the zigzag pattern, you can do it on a smaller scale. Measure the dimensions of the portion of the center wall. Purchase a large blank rectangular artist's canvas and enough of the wallpaper to cover it. Center your completed artwork on that wall vertically (you'll want to orient the canvas where short sides are horizontal and long sides are vertical). The trick here will be correctly sizing the canvas: You want it to be big enough to serve as a focal point piece of art, but not so big that it looks like you've wallpapered or the pattern visually overwhelms the space. If you choose this option, you will want to paint all surfaces on that wall the same color, and let your canvas be the star.
I think the lime green and brown striped wallpaper beats the zigzag by miles. We may have different taste but that zigzag wallpaper looks nasty, if i were you i'd go with the stripes.
I want to put the wallpaper on the middle wall which sticks out like in the picture below except I don't have a fireplace.
https://www.google.co.uk/search?q=middle+wall+sticking+out&source=lnms&tbm=isch&sa=X&ei=BrKkU_CrEo6u7AamyYGYDA&ved=0CAYQ_AUoAQ&biw=1920&bih=845#q=livingm+room&tbm=isch&facrc=_&imgdii=_&imgrc=MDqUf5fg2qXoAM%253A%3BYQeMSRsjW9asuM%3Bhttp%253A%252F%252Fhomedesignmagz.info%252Fwp-content%252Fuploads%252F2013%252F01%252Fwhite-natural-living-room.jpg%3Bhttp%253A%252F%252Fhomedesignmagz.info%252Fcategory%252Fliving-room%252F%3B1024%3B768
The two wallpapers I'm torn between are these:
http://www.ebay.co.uk/itm/Luxury-Designer-Wallpaper-Lime-Green-Black-Retro-Zigzag-/111366189537?pt=UK_Wallpaper&hash=item19edf131e1
http://www.ebay.co.uk/itm/Lime-Green-Brown-Cream-Striped-Wallpaper-/271525520620?pt=UK_Wallpaper&hash=item3f382ea4ec
Also what carpet should I choose with either of the two wallpapers?
