SP Systems Excalibur softbox + Alien Bees ?

Considering the fact that I'm wanting to start studio-type shoots in my garage, but also need to park the car in it when I'm not shooting, I'd like to find a decent sized softbox that I can put together and tear down relatively easily and quickly.

My first look into something like that is with the Excalibur softboxes, as they can open up like an umbrella. For my needs, that would be sweet if doable. The problem is fitting one of those on an Alien Bees light... I know they have a suitable speedring for their smaller softboxes (EZ-Softbox), but apparently nothing for the Excalibur series. Has anyone had any better luck?

I've seen that feature in Norman products as well, but at the moment those are a little out of my price range.

If something that simple is available for under $200, or at the very least something good that's quick in the setup/tear-down department, I'm open to those recommendations as well.

Thanks!

I just got a AB-400 light and bought a 60" softilter by photek. It is simple to put together and the light is amazingly natural looking. You dont need a speedring for the light either. I would describe it as a softbox/umbrella combo- the best of both worlds I think I paid around $80 for the softliter from B&H.

Thanks for the input! I've read some reviews on the Softlighter II at FM as well, and have one on order that should be shipping in a day or two.