Resolution: 1280x1024 (I know, to most it's a low resolution)
I know the amd athlon 2 x4 640 will bottleneck some if not most games. I'll probably be playing mostly the Stalker series, Company of Heroes series, Men of War series, maybe Metro 2033 (heard its gpu intensive), some older games, and some 2013 games.
I'll probably upgrade to a core i3/i5 haswell or ivy bridge next year though.
you are definitely on the right track in my opinion. your CPU is just fine at that resolution. heck it ain't exactly awful at 1080p, although there's a lot better too. but that's beside the point. the 7850 is a great card and will be overkill for you until you upgrade your monitor.