Investing money on this rig is a waste of money if you ask me that can rather be used to buy new system.
Since you say that you are a bit of a gamer then I suggest you buy a whole new system. Haswell is around the corner - a good reason to upgrade. Feel free to keep the monitor but a 1080p won't cost you a lot and you will see a the eye candy that a gamer wants to see at higher resolution.
Tell us when you plan to upgrade, so that you can make a great build that will last some time.