Are you using low voltage or incandescent lighting? If you use low voltage, you can rotate the light bulb in the socket and also vary the width and intensity, color, etc. of the light beaming from the ceiling to acheive the desired lighting requirement. What do you plan to utilize the ceiling lights for? a walkway, reading, general lighting, etc? Remember to take the angle of the lights you have beaming toward the fireplace and make sure the beam clears the mantle. too many times, people put the lights up there and forget the extension of the mantle and it blocks the fireplace they wanted to light up. Just a thought. Low voltage or adjustable ceiling lights will/can correct this if it's already installed. This is a picture of my living room with a vaulted ceiling only to approximately 13-14 feet. We placed a "square" pattern of 4 lights around the seating area to illuminate that, then a "curved" pattern of 4 lights illuminating a preceived walkway thru the room, then we placed two lights to beam into the fireplace, and 4 more lights to illuminate the entrance of each patio door extending off of this room. Our lights are low voltage and you can see the size of them in the far back area of this room. This is the pre-finished ceiling, hopefully, altho blurry, you can pick out the way we put the lights. Think about furniture placement and where your guests will sit, you don't want a beam of light blinding them, you want the room to feel illuminated, yet soft and inviting. Too much information, sorry, but I remember dreaming many nights about my lighting plan and I know it's importance to light a room the way you will actually live and utilize that room. If you have more questions, I can try and take a picture of the ceiling itself to show you the layout of our lights. V

Thanks for suggestion. I was thinking about having a chandelier, but I have heard that a fan is almost a necessity. The room is going to be used for a dining room as well as a sitting room, so I feel I need some kind of light over the dining room table, but the table is not going to be in the middle of the room, but to one side... Any suggestions? Also do you have sconces? I want to have free wall spaces...

Look on this link http://www.lightkulture.com/brands/Sonneman.html  They have interesting drop lights and chandeliers

Jslazart and sprink1es have given you the best advice. You need to consider orientation of the windows (N,S,E,W) before picking windows and narrow your choices accordingly. If they face west, you won’t see the TV in the afternoon, if east the tv will disappear in the mornings. If south, you’ll welcome the warmth in the winter but will miss mid-day TV. If north, the TV will be fine, but the room will feel colder in the winter. Dependent on trees and potential blockage of course.