You can't actually access all 4GB of VRAM without hitting a massive performance wall. The internet is flooded with this news, and over on the https://forums.geforce.com/default/t...-issue/geforce forums, there's a single thread spanning over 280 pages from users looking to demand refunds.
Here’s a video on how Nvidia screwed over their customers (via PC Expert):
In my opinion, the Intel Core i5-3470 is a better bet for gaming than any AMD processor currently out there. At 3.2 GHz, it pulls in results that match or even beat the FX 8350 at 4.0 GHz—and they're priced about the same. You can also overclock it up to 3.8 - 4.0 GHz, all while pulling less power than the AMD alternative.
You didn't list your power supply. If yours isn't up to the task, you can grab one here. That graphics card comes factory overclocked and features dual fans for better cooling. It’s more than enough for your resolution. Given how cheap memory is right now (4GB for $57), there's no point in settling for just 2GB.
If you already have a solid PSU, the price drops to $133.