I use a couple of flood lights (150W each), purchased at an ordinary home supply store. I suppose they are to be used outdoors for lighting up the driveway, garden etc...
As a third overhead light source I use an ordinary floor lamp. All lights are covered with heat-proof paper to diffuse the light. Since these are ordinary light bulbs the camera needs some kind of filter in order to achieve correct colours.
At about USD 10-15 each for the lights I like to think got away rather cheap and I must say this budget set-up works well for my needs.