Fotodiox makes a series of lamp heads that take multiple bulbs. They're square grids with 16 sockets, and there's a less powerful version with I want to say 9, but I don't remember (I have the 16). They're not expensive, and output a tremendous amount of light. I would recommend getting some kind of light control device with them, like a softbox with removable front diffusion panel, because otherwise they spill light all over the place.