Softbox for Flashes and Coollights?
 

I'm going to pick up a couple fluorescent bulbs from coollights.biz.
I currently have a 42" umbrella that I was going to use, but would prefer to use a softbox.

Does anyone know of a softbox I can use with these two bulbs (probably this bracket to mount them: Twin Lamp Bulb Holder E27 Socket Flash Umbrella Bracket on eBay.ca (item 330492298012 end time 01-Feb-11 08:22:17 EST))
and that I could also use to mount a flash to?

edit:

I found this "cheat" to use speedlights (flashes) with a softbox. So the big question that remains is can I use that dual flash holder with any softbox?