Slow saving of files could be fixed by disabling 'Redefine thumbnail on save' in 'Model Info - File'. Maybe it helps with your problem as well.

The e-mail got lost in the mail? One thing I should have added in my previous post is that you can think like a studio photographer for this kind of thing. You can place your model on a seamless background which is easily drawn in SU or you can even find a few on the 3DWH if you're lazy. Place your lights to provide the required modeling (as in shadows) and to light the background as needed. You can put lights behind the model if needed just as a studio photographer might. Making the background an emitter would be like placing the model on a translucent background with light from below/behind. Good luck.

Great help, thanks TIG