Just a little comment about this product or any beauty dish that would use a speedlight; a beauty dish really needs a bare bulb protruding through the opening to have the desire effects of a beauty dish.
With a beauty dish the center baffle blocks the direct light (not reflect) and the light of the bare tube shoots outward and bounces off the side and back so the hottest light is coming from the perimeter with softer light coming from the back witch makes for very contrasty light.
Anytime you use a speed light, the light never directly hits the perimeter. There really isn't a efficient way to get a bare bulb effect. Maybe with a Stofen on and set to protrude but you lose a lot of power since the speedlight light is still really shooting forward.
I'd suggest instead of spending $180 on that bracket, I'd suggest a AB400 (or better if budget allows) and PCB Beauty dish. It will cost $100 or so more but it is real beauty dish light. Plus it comes with diffuser and with that it is essentially like having a 22" round soft box too.
If you really look at the dynamics of what is happening with a beauty dish w/speedlight, it becomes a really crippled flash in a small umbrella. The hottest light is coming straight off from the back with some residual bouncing off the sides just as an umbrella would. So you could really save money and buy a 28" umbrella and have way more efficient use and better quality of light.