Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.
Not worth the upgrade.
Gaming-wise you already have a very capable cpu.
Sayin that your motherboard ony has 1 x16 pci2.0 slot the other runs in 4x, not sure if that would be much of an issue for sli
Sorry man, there is no 2nd x16 size graphics slot on that motherboard - the only other PCIe slot (other than the main x16 one) is a tiny x1 slot.
Also, the board doesn't support SLI or CrossfireX for obvious reasons.
May I ask what your particular issue within ARMA2 is, and what resolution do you play at?