Angle bracket for light stands?

Hi Guys, I've just bought two light stands for my speedlights. They have a qtr inch thread so my trigger receivers screw on and the light fits into the build in hot shoe. Great,I can adjust the height angle etc of the head but I'm now stuck in landscape mode for the flash face.
Is there some sort of 90 degree knuckle or similar that I can put between the stand and the receiver.
At the moment I'm strapping my speelights to the shaft of the light stand with elastic bands. Not an ideal scenario.
Any links would be helpful, don't realy want to invest in booms etc unless I have to.
Cheers,
Eugene.

I use umbrella brackets from Cotswold photography. Or their softbox, which comes with its own ball head bracket.

Does somewhat depend whether you want to put a modifier on the stand as well?

I'm happy with the Cotswold stuff for the price, good quality and fast delivery.