centaurius :
Go for the i5. IF you can get the i5 3550p even. Since you are not gaming at 1920x1080, the more load will be on CPU in various situations. The bigger the resolution the more workload for the GPU, the lower resolution more workload on CPU. Therefore Invest in a good CPU for the next 3/4 years. Get the 7850 (or a 660?) and in 2 years you can get a better GPU (middleterm wise) that the CPU will still be able to kick juice enough in it.
For his resolution, A better Graphics card would be needed because the Resolution he is using is more GPU than CPU. If it were 800x600, then it would be more CPU intensive.
-IDEA: You can always go fan and AMD 6 core black edition CPU, even though they lack intel a lot at gaming, you can overclock the AMD CPU a lot then since it has 6 cores, it would be a bit better at gaming for quite the same price. Other links on this forum have suggested that an AMD CPU would be better at gaming than the i3 3220. If that were your approach, you will need a new motherboard with AM3 Support.