I use a Morris Bare Bulb slave http://www.themorriscompany.com/Lights/ac_barebulbslave.html
in a home made holder atop an old microphone stand that I cut down. It is cheap, works great and isn't so powerful that one needs to stack a bunch of ND filters on it when using it close to the background and it puts out a perfect round spot of light.
Benji

