http://www.amazon.com/HDMI-Splitter-Por ... 3+splitter
something like this?
It makes no sense to try to output the same image to 4-6 projectors using all the Macs outputs, as you take a frame rate hit every time you add a new slice/display. Better to buy a couple splitters and take load off the GPU. Then you can make sure you're around 60fps at all times. If you want to have unique video on each of the 4-6 displays, then you will have to have a pimp computer indeed.
BTW you're using DXV, right?