With your currrent CPU would suggest 2x4GB in 1600/9 or better - if in the budget look to 18866/9, might not be able to run them now at 1866, but can at 1600, then when you upgrade the CPU the DRAM will be waiting...Think I'd suggest looking at the 1866/CL9 1.5 GSkill Snipers, if it doesn't fit the budget, drop to the same in 1600/9