Alright here are my suggestions:
-You might benefit more from the core i7 due to its multi-threading
-get 4GB (or 6GB if you go i7). It will be enough for now. Down the road, upgrade to 8GB (i5) or 9GB (i7)
-Don't cheap out on the hard drive for your build. Get a WD Black 1TB. If you are willing to spend more, start looking at Solid state drives. The solid state drives would be expensive but would satisfy your speed needs and your energy efficient side.
-forget a "dvd player". a DVD-RW drive will play your DVDs. In today's market, the tech for dvd drives has been for so long that anything will do. Get a sata drive though to save on cable space
As for the graphics card:
-Get a radeon 5670. Good all round, low power, DX11, future features.
-However it also depends on which games and what resolution and quality you intend to play them on.
-I like the antec three hundred. It is fairly quiet on low fan speed and on that speed, will give enough airflow. However, it gets louder if you turn up the fans.
-The top may occasionally vibrate. a simple solution is to put a book on top of it in front of the top case fan (not on the fan)