I am using a late 2009 i7 iMac as my main computer currently. I may replace it soon with another iMac. However, I would also like a notebook so that I can do some photo editing on the go and so that I have something portable if I attend workshops that require you to bring your own computer (at the moment I only have a Windows laptop issued from my work for portable needs as well as my personal iPad). Since I expect to use a desktop most of the time, I would prefer to keep my cost down on a Macbook purchase. I do, however, want to make sure that it will be powerful enough so as not to be frustrating when using it. What would you suggest as the minimum specs to look for? Alternatively, would it be worth considering getting a more powerful Macbook and connecting it to a large monitor for home use? Thanks.