I have just started 5 boxing(and 2 and 3) 6 weeks ago. (a little knee surgery and 6 weeks of non-weight bearing is good for my gameplay). Anyways I started with AMD 3600 4GB Ram(8 but windows 7-32 bit) and 660Ti video card and was able to run a 5 box on the Fair setting in wow. And had 45 FPS not in org. I have since upgraded everything but I was able to run good enough. Just wanted to to let you know what I was able to run at if it helps. I believe you got the best advice from the other posts. Good luck.

If you do upgrade video card, just got the 970, wow it rocks. I tried (why I don't know) the amd 290x it was 2x as loud and didn't run near as good, no matter what the test show.( not saying 290x is better but its about the same in most tests)