Hmmmm ... not many manufactutrers use the watt-sec rating ... most just give guide number for ISO 100/21 film. In any case, I think some "potato masher" units fit your requirements ... either with capacitor in handle or in separate shoulder strap suspended power pack. How about the Metz 70-MZ 5? or the Sunpack 622 Super Pro? I think both equal or exceed 150 w/s and both have partial power mode capability. Andy
