There is a larger portable head with four tubes plus a modeling light, and there is a small head that is the same size as the regular LH2 head with a plug for a small quartz modeling light that is mounted on the reflector, and these are light enough to use on a camera bracket, but the 400B pack is pretty heavy. Better on a shoulder strap than a belt, if you want to keep your pants up. I'm not sure if the modeling light heads can run off the 200C pack, which is much smaller, though it also has half the power.
In that video of Winogrand that was floating around recently, he was shooting a parade a night with his Leica and a Norman 200B on a shoulder strap with an LH2 head and 5" reflector on a bracket (no modeling light as far as I could tell). The 200B is the same size as the 400B, but not as heavy.