A couple of additional options to think about. Metz also makes several models of battery-operated units with fairly high light outputs, which makes them more suitable for use with modifiers like softboxes or umbrellas. If you need light levels that are more similar to studio lighting, you might consider the Alien Bees line of studio strobes. There is a battery pack available for them which makes them quite useful for location work. A couple of other studio strobe makers have similar on-location battery packs, as well.