Video card doesn't really matter as they have so little impact on 2D performance
Processor you want dual core - whether intel or AMD it is really down to personnel preference.
RAM - you really want to be looking at 2GB or more, although this will very much depend on how much image manipulation you are going to be doing. If you are going to be dealing with simple point and shoot camera pics then not that much, however if you happen to have a top of the line SLR taking 15MB RAW images then you will want a bit more.