Here's a scene by BdB (bertrand benoit), a friend.
It has the ball thingy as a diffuse material with white emission colour,
and there are 4 quads above the main living area illuminating the front of the room.
The environment is just a black eg value 0 'floattexture'.
This is with the brand new area lights code, it's not efficient yet,
but with a 29 minute render time on a GTX480 i'm very happy

I loaded the obj in and did some minor tweaks while having coffee to set up the mats (it's a very old blender scene),
so the mats aren't very %100.
Rendererd at 4096x2880, then downscaled to 1280x900 with a bicubic filter, no post proc.
Radiance