I've been using two 580EXll speedlites and a Vivitar 285HV hotshoe flash for the portability factor. I have them on lightstands as well as having some modifiers. In this case, I had a 580EXll firing into a 16x24 softbox on subject right. Positioned above and forward of the subject. Another 580EXll with a lumiquest snoot to light the dogs face and subjects arm area. The Vivtar is on a lightstand about 6ft high on subjects left and rear shooting towards top of her head with a flag/reflector guiding the light sideways towards the background as well. the bg was a greenish color linen from a fabric store. $4 bucks a linear yard and 5 ft wide.
All the flashes are tripped with the Cybersync radio tx/rx.
I'm looking to eventually get a White lightning head for greater power and versatility but will get the portable power pack to go along with it so it can still be taken easily to a location where there is no power outlets.