I would suggest, if you have the money, to get the 4 megapixel camera.
I have a 5megapixel, and my mom has a 4 mega pixel (or higher), and when you have the images printed they come out beautiful you can hardly tell they're digital. With other cameras (less mega pixels) it is much more noticable. I don't know much about the cameras mentioned, but if it were up to me I'd get the most megapixels.
tricia.