I have had great success with three manually-controlled speedlights, off camera on light stands, triggered by cheapy Cactus wireless triggers. I incident meter with a flashmeter, plugged right into the Cactus transmitter.

When it's really important, I can pop a proof shot on DSLR or with a polaroid back for the Bronica -- but I rarely make any changes because the flashmeter has removed any guesswork or trial-and-error. You know exactly what exposure you are getting, in what ratio. I find it's easier to tweak ratios by just moving the fill flash closer or further away -- especially on a busy location, sliding a light stand back a couple of feet is much quicker than wrestling with the digital pushbutton controls on the back of the flash.