I wouldn't replace that with some Korean monitor (but that's just me). More RAM only if you really need it (or if you only want it), your CPU won't benefit that much from RAM OC (a better CPU cooler and a higher OC would be better). Socket 2011 is a waste of money since (I assume) you are more into gaming than some heavy computation or VM's. SLI would give you a good boost but I think it's out of your budget if you need a new motherboard, however if you do choose to go SLI then using higher resolution monitor will put those GPU's to good use (1920x1200 won't benefit that much from it). But it's the most expensive way (you need a new GPU, monitor, and motherboard I assume). If I had the hardware that you have and wanted to upgrade something, I would save up and buy a proper 2560 x 1440/1600 monitor. It will have an impact on the GPU, but I think a 670 should be good (if not, save up for another or wait for new generation of GPU's).