I am looking to get an iMac. I am looking at the entry level one 21.5", 1.6 ghz. My main interest is to use it for browsing, photo storage and some photo editing on Lightroom. I am no photographer but do take lots of pictures of my kiddos. Would this computer suffice for my needs or should I spend the extra $300 on the 2.8 ghz 21.5" one? I would like to add that if I later find myself getting better at photography then I would want a better computer, obviously. I would likely want a 27" iMac or a Pro. This most likely won't be for a couple more years since I have a baby at home and not a lot of time to learn. This computer would then become one for my kids for school and such. So, help!! Which one should I spend the money on?