I'm no expert in this stuff or anything, but I know that there are PS2 to PC gamepad converters. However, I don't know how well they work and I suspect it's kind of a jerry-rig, so I wouldn't expect much better than that Wal-Mart purchase you made. I've heard an xbox 360 controller is great for PCs. I also have a logitech Wingman 2 wireless rumble thingie that's really good though I wish the sticks stuck out JUST a little bit less. Otherwise it's great and hassle-free

As for your saitek, I know I've used an older cyborg for space sims, but that might still be a flight sim. I'm not really sure why you'd WANT to use it for any other sort of game, but I'd imagine your computer would think of it in the same way as a gamepad. Try it out!