Yes, the Lime takes the place of the white. Previously, the S4 Studio HD fixture used a Mint Green LED, which is probably the same color. It adds quite a bit of output to the brightness.
Check out Leviton's D4DMX dimmers. We've sold a ton of them and haven't had any problems. Just make sure you order the correct DMX pin configuration for your system.
The Matrox TripleHead2Go is definitely the way to go when you're on a tight budget. Search for refurbished units and you could save some money, too.
As long as the brightness and lenses are the same between projectors, you should be able to do a very respectable full screen image without...
Just started looking through the postings. I work for John S. Hyatt & Associates in Grand Rapids, Michigan. I also do the occasional projection design for some of our local theatres.