Hi Cougo,
Your best best would be to buy an aftergolw xbox controller from Gamestop or one of the "big box" stores. I know Wal Mart also has them. It has a USB cord that plugs right into your PC. Next, you will want to download a program(app-I'm an old fogey LOL) called " Xpadder". This is a button mapping program that lets you assign buttons of the controller to keystrokes on your keyboard. So, your WASD and direction keys could be "mapped" to the control stick. All of the other shortcuts that you use in the game can be assigned to the controller as well, provided you already have them assigned on your viewer. I would, however, reccomend that you still aim and fire with your mouse. FPS games are always a little better on PCs for this reason. PM me if you have any more questions.
Azuro.