Keep in mind, for windows 7+ I had to change the friendly names of each web cam so that Processing can address each one consistently. Here is a tutorial: http://www.eightforums.com/customization/15321-tu...
Also, here is an Instructable to hack the power supply: http://www.instructables.com/id/Converting-a-compu...
The actual build will probably vary so I don't have any real details about that up here..
The code is fairly modular and you should be able to reduce/increase the number of webcams or shutters/servos by changing only 2 or 3 variables.
I would also recommend trying an adjustment in the code: instead of counting blue pixels to refresh shutters according to amount of movement, build an array that drops that oldest pixels so that you don't have too many servos moving at once (big power surge). I might try that later and update the GitHub..
For stabilizing, I drilled a tiny hole in the bottom of each shutter, and a slightly larger hole in the wood sill at the bottom, and inserted an un-popped pop rivet. I used a rivet because it has that little flange built in that was perfect for separating enough that I didn't need to use any lubricant or washers. They Komatex that I used for shutters was a little thin still, hence the wobbling. ALSO if I were to do it again, I'd slow down the shutter movement just a little to help prevent that a little.