What products would you recommend for softbox use of off-camera 580 EX II? I already have stands and multiple flash heads (1x580EX II, 2x580EX). I will be purchasing the new PocketWizards once they're available, but as of right now I'm limited to Canon's E-TTL. I just don't know the best mount system or brand and size of softbox. I will be predominantly shooting 1-2 people in the frame, consisting mainly of head and 3/4 shots. I need to be portable and cordless. Also, I have umbrellas and have shot with them successfully, but have heard how much better control of light you can achieve with softboxes. I'm interested in your thoughts on this. Any recommendations would be greatly appreciated!