I Apple'd the extry 4GB of RAM,for 200 clams. Fuck it I figured and am turnkey.
Didn't procure any software and am in very good shape there and the only thing I may snag is Lightroom 3.
Oodles of RAM is never a mistake, & IMO, you just can't have too much, especially when dealing with imagery.
On software, keep in mind than PC software you may have will not run on a Mac.............
MM