So get the 3225? I won't be gaming until I get a video card.
Absolutely, get the 3225, particularly since they are the same price; there is no downside.
For games such as civ-4, HD-4000 is perfectly fine. Only when you get to fast action shooters would you need a discrete card.
I think it is smart to build with integrated first, it will let you better assess what you need/want for discrete graphics.