A:AnswerBest Buy only lets you choose the processor speed. If you want to change the size of the drive or amount of ram you have to do that from Apple's website. Although it's cheaper to buy extra ram on your own from Amazon and install it yourself; the 27" iMac makes it very easy to do that.
A:AnswerIt really depends on how you are using it. If you are an an avid photographer or graphic artist, you should have 16GB RAM. Frankly, adding more RAM is not expensive,
like $200 more, so yes, more RAM always.
