Get a 2 x 4GB memory kit. 8GB total. And a mid tower should work OK. If you are getting a GPU, make sure the specs of each will fit. Most GPUs will fit in most mid towers.
@spooky,will two 4 gb 1600 mhz sticks work in a good way with this Kaveri processor? Can I play some games such as hot pursuit,black ops 1 without GPU?
My main purpose of this machine will be for photographic works. Games come later..for some time.