I have one stainless steel bracket that will adapt 2 or 4 speedlights on it so you can shoot all 4 using just 1 umbrella. Basically it allows you to gain significant power by using multiple speedlights at the same time. This is not like the cheap ones you see on ebay or other wierd name brands. It's made from solid satinless steel, 1" x 1" thick. Basically significantly sturdy enough to handle multiple speedlights.
Selling the one I have for $150 + $15 shipping NET to me by paypal or EMT to anybody in Canada.
I'll be doing my best to post some pictures when I get back into town this week.