A little background: I have a Canon 30D, a 580 EX speedlight, and a 24-70 2.8L. I am trying to photograph dogs at night in very low light. Due to the lighting I am looking for a wireless system, with a high sync speed. I have to shoot 1/640 sec to stop the action. The pocketwizards and the quantum units have a cut off at 1/250. The Canon system doesn't have the distance that I need to keep the enviorment safe. I've tried the 580 at all kinds of settings and with a diffuser (lightsphere) and can get a balanced look, due to how dark the enviroment is ( have no control over this, it is rarely done in the day, or places with decent light at night). I can't afford the big strobe units and having extention cords to light work lights would be a hazard. I am looking for a kit with hotshoe flashes that I could use for this application as well as other (portait or candid) work. Can anyone recommend a wireless system as well as flash units that would be good in this type of situation? Thanks for your time and responses.