1. Go for the 2 gig cards, they are known to be totally compatible, the 4Gig cards have some history for substandard performance, incompatibility and sticking int he camera. Also they are lot cheaper and easier to find.
2. Dont be in a rush to buy everythig at once. If this is your first DSLR then you will need a little while to get used to your camera and what style of shooting you like to do, Portraiture, landscape, action, macro, night, sports, candid and so on.
Then buy the leses and or flash you will need/want, i.e. the 540 flash versus the 360. Depending on what sort of photography you decide you will do will determine if you NEED the 540 other wise you could get away with the 360 at a lot less cost.
Good luck and enjoy your camera.