I'm really interested in your idea for strobe exposure for contact printing. sounds like a great idea. My only thoughts are with the multiple heads you will need to support them above a piece of diffused plastic. Far enough away that the lights overlap each other for even light coverage. As far as how many pops really depends on how many watts your driving through the heads. With 6 heads however it's not going to take much. (I'm guessing) My current setup is a light bank is 6 24 inch 300 watt black lights 4 inches above the contact plate. My exposure times are around 10 minutes.
Please keep us posted I'm curiousto see how it works out.