1080p Crysis2, i3 IVB, HTPC, what GPU?

Hello everyone. I've been a longtime lurker under a different username but it apparrently got locked due to inactivity so this is my first post under this name. I am upgrading my HTPC with an I3 w/HD4000 graphics, 4G RAM, W7 MCE, Z77 mobo. I think now that I may have whiffed on my processor choice as I really like the HD4000's HTPC capabilities but I've decided since I am moving my Xbox to the bedroom as an extender, I'd like to do some gaming on the HTPC itself.

It's a full ATX case (Silverstone from about 7 years ago) and has pretty good airflow. Gaming res would be 1080p. I'm basically looking to see what I should look at for a GPU that can play something like Crysis 2 but not be CPU-bottlenecked. I do not require Extreme settings and so forth. I'm a huge fan of the CryEngine games (not even sure if that's what they still call it) but could see myself picking up BF3 and COD:BO2, and so on. So, what GPU should I look at that will excel in both media playback (MKV, BluRay, etc...) and put on a decent show for gaming when coupled with 4G of RAM and an I3 3225? My gut is telling me something along the lines of a 7750 or 7770, but not sure what the similar card is from the green camp.

Any help is much appreciated!

What PSU do you have?
Which Silverstone case?

I'm using a max OCed 650 Ti (I got it for the Assassin's Creed 3 bundle) and I can game at 1080p max settings in most games. I'm pretty happy with it.