I am planning on buying the 20 inch iMac any day now. I will use it for some video editing, garageband, internet, microsoft office applications, itunes. I am planning on getting the 400GB HD and wireless keyboard/mouse, but am undecided between the 1GB or 2GB memory? Any suggestions? Also, is there anything else I should add to the computer. I've heard that I should not buy memory from apple, however I've also heard that when you buy from a third party vendor the apple protection plan will not cover it. Any suggestions? Thanks in advance for your help. I am very excited.