One more thing to the OP. Before making a huge investment in the Mac systems, consider that Apple is moving away from desktops to be a mobile company. Do not be surprised that in a couple years, the OSX as we know it will be gone. You already have many open source projects eliminated from the OSX, stuff like VLC is not going to be OSX supported after release 1.1.
This is a concern that I would have.
This is a concern that I would have.