Are you lighting an automobile? I'm curious to know why you need an 8' softlight suspended in the air? There may be other ways of going about it.

I built and suspended the rig today. It works quite well and I managed to keep the heat levels down by adding some strategically placed vents.

I ended up using 18 100w bulbs. The whole rig cost me $60. It's now quite as bright as I had hoped, but it will suffice. I have a few ideas to brighten it up tomorrow.

All in all it was a success and I want to thank you all for your input.

And in response to Hunter, it's a set that features a pool table. I needed an inexpensive (and massive) softbox over the table to produce nice reflections in the balls.

I see, you want to create a pleasing specular highlight on your pool balls.

You can always move a smaller light source with diffusion closer to the table, but I guess you are trying to stay wide?

Anyways, here is a very cool article on maintaining proper specular highlights on shinny objects. It might be helpful for photography of pool balls too!:
http://photo.net/bboard/q-and-a-fetch-msg?msg_id=007tNJ

Exactly.

And thanks for the link Hunter...but it doesn't seem to work.

"Couldn't find message 007tN. It was probably deleted by the forum maintainer."

Either way, the shoot starts tomorrow, which unfortunately means that I don't have any more time to invest in this lighting rig. Thanks though, I appreciate the all the help I can get. :)

Oops! Fixed the link.