Ellis Below is a link to the new softbox I'm using for teaching. It is an excellent buy. Uses a 70 watt CFL. It doesn't put out much power but in a darkened room it works great.
In the photo of Kim's piece I did use a softbox but you really don't need one. If you move the light back far enough to light most of the panel that in effect becomes your light source. Larger light means softer light and soft broad reflections. If you go back and look at my segmented vase for all practical purposes the reflection looks about the same. I simply moved the gridded reflector light back far enough to light most of the left panel. That gave a light very similar to the soft box.
What I like about softbox in the link I gave you is for a lot of things you may not need the panel. Panels tend to spread the light and make it hard to control the light on the background. A soft box gives you a little more control.