Digital is NOT a good polaroid substitute! I have yet to see a digital camera whose ISO 100 is the same as a handheld flash meter's ISO 100.
It's easy enough to figure out that ASA125 on your meter is ASA100 on your camera, and the digital makes a great Polaroid. In fact, digital hits its peak in the studio under controlled lighting and contrast, just as film does.
I routinely make flawless 20-30" prints from a Canon 5D. I couldn't make a living shooting studio portraits on film.