Ok, on the fence now for a new Mac Pro, but I don't seem to get a couple of things. I need someone to help me get a grip of the graphics card BTO options... For example, I'd like to be able to, sometime down the road, expand to 3 displays for my work. That said, I'd like to get the HD 4870 for the extra graphics boost, but why can't I add a GT120 during customization? Is it due to hardware conflicts of having both an Nvidia and ATI card at once? If thats the case, why then, can't I add two HD 4780s to my machine, instead of multiple GT 120s??? But honestly speaking, I really don't need two two top of the line BTO cards. Which is why ideally, I'd like to spend less and just get a GT120 as my secondary card, but seeing as there are no BTO options for such a combination, my mind is boggled at the moment.