Probably like everyone else on this forum right now, I'm buying a new iMac on Friday. Probably unlike everyone else, I have no idea what I'm buying. I've never owned a Mac before, but I'm fed up with PCs. My question is what model and what upgrades do I need? I intend to mainly use it for very baisc things like iTunes, Microsoft Office, watching movies, etc. I am also getting into Photoshop and video and music editing more and more. The main thing I'm looking for is longevity. The past few computers I've had lasted about 1.5-2 years before they started to limp along. I'm looking for this one to make it to about 4 years before the limping starts. How neccessary is the i7, fusion drive, and 16gb ram for these things? Thanks in advance.