Oddly enough the ceiling is crucial, even if you don't think to look at it, your subconscious notices it. Lower ceilings will make you feel crowded and uneasy. White tile ceilings lower your thoughts on how classy the place is and make it seem outdated. I always thought a high black ceiling with burlap coffee bags hanging from it, and some track lighting, would look cool for a coffeeshop. You could skip the burlap coffee bags.
Tables-chairs: they should all be different! different sizes, shapes, colors. I personally would avoid glass-tops on the tables because you have to CONSTANTLY windex them to keep them looking nice.
Sofas: must have at least one, preferably leather, tucked into a corner.
Fireplace: yes. one of those artificial ones that double as a gas-heater.
I wouldn't use coffee wallpaper. I'd just paint the walls a solid color and then I would invite local art students to hang their work on the wall for sale. Every few months swap out what didn't sell for a new lineup of art. It will give customers something to look at, it's community-friendly, and it gives you free decorations!
In lieu of that, hire a local artist to paint some abstract trees, birds, and flowers on the walls. You want to provide your customers with an escape. Give them something to inspire them, something to take them away from the worries of the world. Make them feel comfortable, welcome. The coffee will do the rest.