Fang,
I would suggest a gaming computer from iBuy Power or another custom builder. Here's a link
http://www.ibuypower.com/
Mine cost about $2,300 all in and I have been very pleased. Cuts through games like butter and came in about a week, very nicely packaged. Sales guys know their stuff. I am not a tech guy and would not consider building my own. This was the next best thing for me.