I have been eying a Mac Pro for a few months now and want very much to get it soon. However, the "Buyer's Guide" lists it as "Buy Only If Needed". I understand that the guide is not the end all be all, but still makes me nervous. Secondly, it is primarily a video update that interests me in the next Mac Pro. I would prefer, if possible to have an Nvidia card in the machine in the 9000 series if possible. Has Apple ever offered different machine options (ie: video, memory, HDD) without a processor upgrade?