What do you consider essential when customising a new Mac and why? At least a certain screensize? A certain amount of RAM? A certain speed of hard drive or capacity? A top graphics card? etc. Also, do you always get your components (particularly RAM) from Apple or do you buy from a third party? This is mostly out of interest but I'm particularly interested in the RAM results as people seem divided on whether to buy RAM from Apple or not. I myself am tempted to purchase from Crucial but I'm wary about opening a brand new iMac! Does anyone have any tutorials with pictures to show how scary the process actually is?