I'm looking at just renting the above mentioned version of the PW, any advice on using them? How many will I need 4? One for each body and one for each light?
You only need two MultiMax units for the cameras. The handheld trigger and the flash trigger units can be one of the Plus II units that you already have.
Setting up the MultiMax for synchronized shooting is a bit complicated so you would be better off downloading the MultiMax manual from the PW site (http://www.pocketwizard.com/HTML/manuals.asp) and reading pages 41 through 49. On page 47, they refer to a "one unit equalization" and a "two unit equalization". You want to the "two unit equalization".