OK so I am thinking of getting a 580ex to try some off camera strobist type stuff. I was looking at Quantum battery packs but I'm not sure which is the best fit. I dont have any experience with these packs so if someone could steer me in the right direction as far as size,weight and so on. I will probably mount it to the stand but may carry it in the future as I shoot an event from time to time.
Thanks


