DayZ settings hardware help

Well hello guys! FortWaba here, just saying hello to the Verge! Now, I need your help.

My PC settings are:

Intel E8400 3.00GHz

GeForce 8800GT

2GB DDR3

Windows 7

I REALLY need help with Arma II. I'm dying to play DayZ, but the game is terribly optimized, I'm barely getting 25fps on high settings, and that's at an 80% resolution (something x 945).

Any DayZ players here who might offer some suggestions? I need a rock solid 30fps at least. Also, if I had to upgrade something to get at least a steady 50fps, what should I upgrade to?