Looking for a bracket to hold two speed lights

I have the Westcott - Apollo Strip 16 x 30" (40.6 x 76.2 cm) mounted onto a Manfrotto 026 Swivel Umbrella mount and the flash is connected to a SHAPE UNIVERSAL HOT SHOE FEMALE.

I'd like to be able to mound two speed lights inside of this box when needed. Any suggestions?

Edit:

It looks like this may work? I doubt that I'd need three speedlights but it's nice to have just in case.
http://www.fjwestcott.com/triple-threat-bracket

That Westcott 3-flash bracket looks like a decent option.

One thing I always disliked about the Westcott Apollo's (and similar) designs was that you couldn't tilt the softbox at extreme angles

However, I like this solution for fixing the issue (it also has two flash brackets and positions the the flashes so that they are pointed directly at the center of the softbox). It's not cheap, though. I think you could likely make a DIY solution for less.