Paul,
I've been a T&I shooter for 30 years and learned long ago that power cords can be a real pain at times. I would recommend you look at Lumedyne lights (
www.lumedyne.com) for power and versatility using battery power. You can also find these units used at places like KEH Cameras (
www.keh.com) from time to time, and they have a lot of configurations you can use (including power cords if you want).
Another consideration for lighting might be Alien Bees. These are made by the same folks that make White Lightning and are really catching on in some areas due to their lower prices and versatility. They are basically studio monolights (three different power levels available, I believe), and they have introduced a battery system (Vagabond) that allows you to hook up the Alien Bees to battery, so you might find these more suitable for dual purposes.
I have both kinds of lights (but not the Vagabond battery for the Bees yet), and have used the Lumys for many years in quite a lot of shoots. Very tough and reliable portable power.
Neil