[Rof]

video card: i suggest the AMD chipsets(you look at their website for details on the models you gave)...coz its cheaper...NVDIA is a little bit better but the price range is quite large...

DDR2/DDR3: just look at it this way...the higher the number the better! lol! but 3GB RAM is quite a lot...like im only using 2GB RAM right now and dont find any problems...but if your planning to multi task(play fiesta while doing your assignments and photoshoping and etc.)you probably need a large RAM then...

other things: dont forget the processor...always go for the dual core or better...dont go under dual core...im not sure if theres already i quad core on laptops...just check it out...