1. Just as a heads up, you do know that you need a new motherboard for that CPU, right? The fastest CPU you can get new on it's own that is compatible is the Phenom Ii X4 965.
2. Are you planning to do heavy overclocking? If not an Ivy Bridge series i5 would be better on the Intel side.
3. I generally would recommend an AMD Vishera processor, which sacrifices some gaming performance for higher performance in multithreaded applications, and as such the majority of future applications. Though Intel would be faster for Mabinogi.
4. I would recommend One of these sets of RAM;
a}
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220558 - same speed, made in USA, more energy efficient, cheaper.
b)
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148656 - faster, made in the USA. more energy efficient, not much more expensive.
5. Graphics card depends on your budget, I have a guide here;
http://mwomercs.com/forums/topic/10474-general-gpu-guide/