Macbooks are made out of the same components as PC laptops: seagate HDDs, intel CPUs, nvidia integrated graphics. Adobe's suite of utilities is written in C++ which can run nativley on Windows and Mac OSX. So what makes you think that a macbook would do the job better?Naru-Chu: I have personally been impressed with HP's product quality and customer service. I own an HP Pavilion myself, and it runs anything not named Crysis. I bought it two years ago for about $800, so anything you buy now-a-days within your price range should be at least as powerful.
The important thing to remember when getting a laptop for graphical editing is graphics and processor power. Whatever you decide to buy for that price should do the job alright, though from my experiences in the past, Dell's build quality is going to be shoddier than the competition and in the end any dollars you save won't be worth it.