I am about to purchase a mac pro for my studio photographies Post Processing. I am confused as to what 3rd party RAM I should buy to get the machine to 5GB and what HDD's to buy to get up to 1000 GB memory. I am going with the stock MP and am going to change out the components myself. Any suggestions would be greatly appreciated. I will be running, as to software, Photoshop CS 3 and Nikon Capture NX. I understand that the MAC is particular as to its operation with the wrong 3rd party hardware should I make an uninformed choice. Price is an issue and that is why I have chosen to do this the way I am. I have worked on PC's and done change outs of hardware and I understand that MAC is much easier. Hope I don't sound ignorant as to this question, but, I certainly am concerning MAC. Haven't had one since '98. Just wondering what the best manufacturer is concerning all the above is. What is better for a MAC that I can add which will work the best .