MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
Weight of the chamber plate doesn't matter, although the heavier the better as it adds overall mass to the frame. As to the plates for the upper and lower z stage, I myself have no way of knowing if yours are too heavy or not. You can always try them.