Your shot with a third light on the top was the most successful....if you shine the top light more towards the background that will help turn it white. I would first place it almost at the front top and angle it about 45 degrees to the back. Move it around till it suits you

For lights I recommend Alzo Digital, they have 27, 45 and 85w CF bulbs @ 5500k.

http://alzodigital.com/online_store/...ment_lamps.htm

Cheers, Don